// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_SITE_INFO_H_
#define CONTENT_BROWSER_SITE_INFO_H_

#include "base/unguessable_token.h"
#include "content/browser/agent_cluster_key.h"
#include "content/browser/embedder_isolation_info.h"
#include "content/browser/url_info.h"
#include "content/browser/web_exposed_isolation_info.h"
#include "content/common/content_export.h"
#include "content/public/browser/security_principal.h"
#include "content/public/browser/storage_partition_config.h"
#include "content/public/browser/web_exposed_isolation_level.h"
#include "url/gurl.h"
#include "url/origin.h"

namespace content {

class BrowserContext;
class IsolationContext;
class OriginAgentClusterIsolationState;
class StoragePartitionConfig;
struct UrlInfo;

// SiteInfo represents the principal of a SiteInstance. All documents and
// workers within a SiteInstance are considered part of this principal and will
// share a renderer process. Any two documents within the same browsing context
// group (i.e., BrowsingInstance) that are allowed to script each other *must*
// have the same SiteInfo principal, so that they end up in the same renderer
// process.
//
// As a result, SiteInfo is primarily defined in terms of "site URL," which is
// often the scheme plus the eTLD+1 of a URL. This allows same-site URLs to
// always share a process even when document.domain is modified. However, some
// site URLs can be finer grained (e.g., origins) or coarser grained (e.g.,
// file://). See |site_url()| for more considerations.
//
// SecurityPrincipal is the interface that's exposed to features that need
// to access security principals outside of //content, providing access to a
// subset of SiteInfo properties. SiteInfo is the sole implementation of that
// interface, for use inside //content.
//
// In the future, we may add more information to SiteInfo for cases where the
// site URL is not sufficient to identify which process a document belongs in.
// For example, origin isolation (https://crbug.com/1067389) will introduce a
// 'keying' bit ('site' or 'origin') to avoid an ambiguity between sites and
// origins, and it will be possible for two SiteInstances with different keying
// values to have the same site URL. It is important that any extra members of
// SiteInfo do not cause two documents that can script each other to end up in
// different SiteInfos and thus different processes.
class CONTENT_EXPORT SiteInfo : public SecurityPrincipal {
 public:
  // Helper to create a SiteInfo that will be used for an error page.  This is
  // used only when error page isolation is enabled.  Note that when site
  // isolation for guests is enabled, an error page SiteInfo may also be
  // associated with a guest. Similarly, when process isolation for fenced
  // frames is enabled, error pages inside fenced frames will be isolated from
  // embedders.
  //
  // `web_exposed_isolation_info` and `cross_origin_isolation_key` describe the
  // isolation state of the error page. Top-level error pages use a non-isolated
  // WebExposedIsolationInfo and CrossOriginIsolationKey, while subframes and
  // embedded content (including fenced frames, protals, etc.) will inherit the
  // WebExposedIsolationInfo value from their embedder and may inherit the
  // CrossOriginIsolationKey (depending on whether cross-origin isolation was
  // enabled by COOP+COEP or DIP).
  static SiteInfo CreateForErrorPage(
      const StoragePartitionConfig storage_partition_config,
      bool is_guest,
      bool is_fenced,
      const WebExposedIsolationInfo& web_exposed_isolation_info,
      WebExposedIsolationLevel web_exposed_isolation_level,
      const std::optional<AgentClusterKey::CrossOriginIsolationKey>&
          cross_origin_isolation_key,
      const base::UnguessableToken& browser_context_id);

  // Helper to create a SiteInfo for default SiteInstances.  Default
  // SiteInstances are used for non-isolated sites on platforms without strict
  // site isolation, such as on Android.  They may also be used on desktop
  // platforms when strict site isolation is explicitly turned off (e.g., via
  // switches::kDisableSiteIsolation).
  static SiteInfo CreateForDefaultSiteInstance(
      const IsolationContext& isolation_context,
      const StoragePartitionConfig storage_partition_config,
      const WebExposedIsolationInfo& web_exposed_isolation_info,
      const std::optional<AgentClusterKey::CrossOriginIsolationKey>&
          cross_origin_isolation_key);

  // Helper to create a SiteInfo for a <webview> guest.  This helper can be
  // used for a new guest associated with a specific StoragePartitionConfig
  // (prior to navigations).
  static SiteInfo CreateForGuest(
      BrowserContext* browser_context,
      const StoragePartitionConfig& partition_config);

  // This function returns a SiteInfo with the appropriate site_url and
  // process_lock_url computed. This function can only be called on the UI
  // thread because it must be able to compute an effective URL.
  static SiteInfo Create(const IsolationContext& isolation_context,
                         const UrlInfo& url_info);

  // Method to make creating SiteInfo objects for tests easier. It is a thin
  // wrapper around Create() that uses UrlInfo::CreateForTesting(),
  // and WebExposedIsolationInfo::CreateNonIsolated() to generate the
  // information that is not provided.
  static SiteInfo CreateForTesting(const IsolationContext& isolation_context,
                                   const GURL& url);

  // Returns the site of a given |origin|.  Unlike Create(), this does
  // not utilize effective URLs, isolated origins, or other special logic.  It
  // only translates an origin into a site (i.e., scheme and eTLD+1) and is
  // used internally by GetSiteForURLInternal().  For making process model
  // decisions, Create() should be used instead.
  static GURL GetSiteForOrigin(const url::Origin& origin);

  // Returns the site URL derived from an opaque data: origin. This has the form
  // data:<serialized nonce>. This is only to be called for data: URLs with
  // opaque origins, and will crash otherwise, e.g. in LoadDataWithBaseURL,
  // where the base URL is not an opaque origin.
  static GURL GetOriginBasedSiteURLForDataURL(const url::Origin& origin);

  // Returns a StoragePartitionConfig for the specified URL. Note that the URL
  // can be both a site URL that was generated by a SiteInfo or a regular
  // user-provided URL.
  //
  // Note: New callers of this method should be discouraged. New code should
  // have access to a SiteInfo object and call GetStoragePartitionConfig() on
  // that. For cases where code just needs the StoragePartition for a user
  // provided URL or origin, it should use
  // BrowserContext::GetStoragePartitionForUrl() instead of directly calling
  // this method.
  static StoragePartitionConfig GetStoragePartitionConfigForUrl(
      BrowserContext* browser_context,
      const GURL& site_or_regular_url);

  // Computes the web-exposed cross-origin isolation capability that should be
  // used for a SiteInfo with the given WebExposedIsolationInfo and UrlInfo.
  // This will be the same as the BrowsingInstance's WebExposedIsolationInfo
  // except for agents that are cross-origin to an "isolated application"
  // BrowsingInstance.
  //
  // See ProcessLock::GetWebExposedIsolationLevel() for more information.
  static WebExposedIsolationLevel ComputeWebExposedIsolationLevel(
      const WebExposedIsolationInfo& web_exposed_isolation_info,
      const UrlInfo& url_info);

  // Computes the web-exposed cross-origin isolation capability that should be
  // used for a SiteInfo with the given WebExposedIsolationInfo that isn't
  // locked to a site.
  static WebExposedIsolationLevel ComputeWebExposedIsolationLevelForEmptySite(
      const WebExposedIsolationInfo& web_exposed_isolation_info);

  // A helper to determine whether a site requires a dedicated process, based on
  // fields from SiteInfo. This takes the relevant bits individually so it's not
  // necessary to create a SiteInfo first.
  static bool RequiresDedicatedProcessInternal(
      const GURL& site_url,
      const IsolationContext& isolation_context,
      BrowserContext* browser_context,
      bool does_site_request_dedicated_process_for_coop,
      bool requires_origin_keyed_process,
      bool is_sandboxed,
      const EmbedderIsolationInfo& embedder_isolation_info,
      bool cross_origin_isolated_through_dip);

  // Exposes functionality of `GetSiteForURLInternal so tests can do effective
  // URL translation.
  static GURL GetSiteForURLForTest(const IsolationContext& isolation_context,
                                   const UrlInfo& url_info,
                                   bool should_use_effective_urls);

  // A specific opaque origin used in origin-keyed AgentClusterKeys to represent
  // the fact that the ProcessLock is not locked and allows any origin. When the
  // AgentClusterKey is site-keyed, we use an empty GURL to represent that it
  // allows any site. But there is no similar concept in url::Origin. In
  // particular, url::Origin() will create an opaque origin with a different
  // nonce each time it is called. This means that two origins created with
  // url::Origin() will not be equal to one another. To get around this
  // difficulty, we define one opaque origin created with url::Origin() as the
  // origin representing an unlocked ProcessLock and we use it anywhere we want
  // to check or indicate that a ProcessLock is not locked to a particular
  // origin or site.
  static const url::Origin& GetOriginForUnlockedProcess();

  // Initializes |storage_partition_config_| with a value appropriate for
  // |browser_context|.
  explicit SiteInfo(BrowserContext* browser_context);

  // The SiteInfo constructor should take in all values needed for comparing two
  // SiteInfos, to help ensure all creation sites are updated accordingly when
  // new values are added. The private function MakeSecurityPrincipalKey()
  // should be updated accordingly.
  SiteInfo(const AgentClusterKey& agent_cluster_key,
           const GURL& site_url,
           bool is_sandboxed,
           int unique_sandbox_id,
           const StoragePartitionConfig storage_partition_config,
           const WebExposedIsolationInfo& web_exposed_isolation_info,
           WebExposedIsolationLevel web_exposed_isolation_level,
           bool is_guest,
           bool does_site_request_dedicated_process_for_coop,
           bool is_jit_disabled,
           bool are_v8_optimizations_disabled,
           bool is_fenced,
           const base::UnguessableToken& browser_context_id,
           const EmbedderIsolationInfo& embedder_isolation_info);
  SiteInfo() = delete;
  SiteInfo(const SiteInfo& rhs);

  // SecurityPrincipal overrides.
  ~SiteInfo() override;
  bool IsSandboxed() const override;
  bool IsGuest() const override;
  bool IsWebUI() const override;
  bool IsOriginKeyed() const override;
  const StoragePartitionConfig& GetStoragePartitionConfig() const override;
  bool SchemeIs(std::string_view scheme) const override;
  std::string_view GetHost() const override;
  const GURL& GetDeprecatedSiteURL() const override;

  // This function returns a new SiteInfo which is equivalent to the original,
  // except that its AgentClusterKey is made site-keyed if it had been created
  // as origin-keyed due to an OAC opt-in request.
  SiteInfo GetNonOriginKeyedEquivalentForMetrics(
      const IsolationContext& isolation_context) const;

  // Additional non-virtual accessor to site_url_, which is ok to use from
  // inside //content. See SecurityPrincipal::GetDeprecatedSiteURL for more
  // info.
  const GURL& site_url() const { return site_url_; }

  // Returns the AgentClusterKey of the execution contexts within this SiteInfo.
  // The AgentClusterKey can be origin-keyed, in which case all the execution
  // contexts in the SiteInfo will belong to a specific origin. Or the
  // AgentClusterKey can be site-keyed. In this case, execution contexts in the
  // SiteInfo will belong to a specific origin and its subdomains. This is the
  // case for most SiteInfos (unless features::kOriginKeyedProcessesByDefault is
  // enabled), and in particular of command-line isolated origins and legacy
  // isolated origins added via
  // ChildProcessSecurityPolicy::AddFutureIsolatedOrigins().
  //
  // Origin-keyed AgentClusterKeys can be a result of an explicit
  // Origin-Agent-Cluster opt-in. They are also the default when
  // features::kOriginKeyedProcessesByDefault is true. In both cases, the OAC
  // status of the SiteInfo will be tracked in |oac_status_|, with values of
  // kOriginKeyedByHeader and kOriginKeyedByDefault.
  //
  // The AgentClusterKey can also be origin-keyed due to other factors beyond
  // OAC. In this case, origin-keying will not be shown in the |oac_status_|.
  // This is for example the case for documents cross-origin isolated through
  // DocumentIsolationPolicy.
  //
  // Finally, some AgentClusterKeys are site-keyed, but with a site URL that is
  // scoped in practice to an origin. This is the case when
  // features::kStrictOriginIsolation is enabled, or for sandboxed data URLs
  // with origin isolation.
  // TODO(crbug.com/433443082): Refactor those cases so that they create an
  // origin-keyed AgentClusterKey instead of a SiteKeyed one.
  const AgentClusterKey& agent_cluster_key() const {
    return agent_cluster_key_;
  }

  // Returns the URL which should be used in a SetProcessLock call for this
  // SiteInfo's process, based on the |agent_cluster_key_|.  This is the same as
  // |site_url_| except for cases involving effective URLs, such as hosted apps.
  // In those cases, this URL is a site URL that is computed without the use of
  // effective URLs.
  //
  // NOTE: This URL is currently set even in cases where this SiteInstance's
  //       process is *not* going to be locked to it.  Callers should be careful
  //       to consider this case when comparing lock URLs;
  //       ShouldLockProcessToSite() may be used to determine whether the
  //       process lock will actually be used.
  GURL GetProcessLockURL() const;

  // The status of the Origin-Agent-Cluster header request for this SiteInfo.
  // This is mainly used to distinguish between SiteInfos that received process
  // isolation for their origin due to an explicit OAC opt-in via header
  // (kOriginKeyedByHeader) from the SiteInfos that received process isolation
  // due to features::kOriginKeyedProcessesByDefault (kOriginKeyedByDefault).
  // The former must be tracked per BrowsingInstance to maintain a consistent
  // OAC state, while the later do not need to do so.
  // Note that this only applies to OAC that is backed by process isolation. OAC
  // can also be logical, in which case it will only apply in the renderer
  // process and is not tracked in the SiteInfo.
  // Also note that having an |oac_status_| of kOriginKeyedByHeader or
  // kOriginKeyedByDefault will make the |agent_cluster_key_| origin-keyed, the
  // reverse is not true. It is possible for the |agent_cluster_key_| to be
  // origin-keyed and |oac_status_| to be kSiteKeyedByDefault, for example in
  // the case of a cross-origin isolated document with DocumentIsolationPolicy.
  AgentClusterKey::OACStatus oac_status() const {
    return agent_cluster_key_.oac_status();
  }

  // Returns either kInvalidUniqueSandboxId or the unique sandbox id provided
  // when this SiteInfo was created. The latter case only occurs when
  // `is_sandboxed` is true, and kIsolateSandboxedIframes was specified with
  // the per-document grouping parameter.
  int unique_sandbox_id() const { return unique_sandbox_id_; }

  // Returns the embedder-specified process isolation policy for this SiteInfo.
  // See //content/browser/embedder_isolation_info.h.
  const EmbedderIsolationInfo& embedder_isolation_info() const {
    return embedder_isolation_info_;
  }

  // Returns the web-exposed isolation mode of the BrowsingInstance hosting
  // SiteInstances with this SiteInfo. The level of isolation which a page
  // opts-into has implications for the set of other pages which can live in
  // this SiteInstance, process allocation decisions, and API exposure in the
  // page's JavaScript context.
  const WebExposedIsolationInfo& web_exposed_isolation_info() const {
    return web_exposed_isolation_info_;
  }

  // Returns the web-exposed isolation capability of agents with this SiteInfo,
  // ignoring the 'cross-origin-isolated' permissions policy. This should be
  // used in conjunction with permissions policy to determine whether a frame
  // can access APIs gated behind cross-origin isolation.
  //
  // This may return a lower isolation level than
  // `web_exposed_isolation_info_` because "Isolated Application" cannot be
  // delegated cross-origin.
  WebExposedIsolationLevel web_exposed_isolation_level() const {
    return web_exposed_isolation_level_;
  }

  bool is_error_page() const;
  bool is_jit_disabled() const { return is_jit_disabled_; }
  bool are_v8_optimizations_disabled() const {
    return are_v8_optimizations_disabled_;
  }
  bool is_pdf() const { return embedder_isolation_info_.is_pdf(); }
  bool is_fenced() const { return is_fenced_; }

  // See comments on `does_site_request_dedicated_process_for_coop_` for more
  // details.
  bool does_site_request_dedicated_process_for_coop() const {
    return does_site_request_dedicated_process_for_coop_;
  }

  // Returns true if the site_url() is empty.
  bool is_empty() const { return site_url().possibly_invalid_spec().empty(); }

  SiteInfo& operator=(const SiteInfo& rhs);

  // Determine whether one SiteInfo represents the same security principal as
  // another SiteInfo.  Note that this does not necessarily translate to an
  // equality comparison of all the fields in SiteInfo (see comments in the
  // implementation).
  bool IsSamePrincipalWith(const SiteInfo& other) const;

  // Returns true if all fields in `other` match the corresponding fields in
  // this object.
  bool IsExactMatch(const SiteInfo& other) const;

  // Determines how a ProcessLock based on this SiteInfo compares to a
  // ProcessLock based on the `other` SiteInfo. Note that this doesn't just
  // compare all SiteInfo fields, e.g. it doesn't use site_url_ since that
  // may include effective URLs.
  // Returns -1 if `this` < `other`, 1 if `this` > `other`, 0 otherwise.
  int ProcessLockCompareTo(const SiteInfo& other) const;

  // Note: equality operators are defined in terms of IsSamePrincipalWith().
  bool operator==(const SiteInfo& other) const;

  // Defined to allow this object to act as a key for std::map and std::set.
  // Note that the key is determined based on what distinguishes one security
  // principal from another (see IsSamePrincipalWith) and does not necessarily
  // include all the fields in SiteInfo.
  std::weak_ordering operator<=>(const SiteInfo& other) const;

  // Returns a string representation of this SiteInfo principal.
  std::string GetDebugString() const;

  // Returns true if pages loaded with this SiteInfo ought to be handled only
  // by a renderer process isolated from other sites. If --site-per-process is
  // used, like it is on desktop platforms, then this is true for all sites. In
  // other site isolation modes, only a subset of sites will require dedicated
  // processes.
  bool RequiresDedicatedProcess(
      const IsolationContext& isolation_context) const;

  // Returns true if a process for this SiteInfo should be locked to a
  // ProcessLock whose is_locked_to_site() method returns true. Returning true
  // here also implies that this SiteInfo requires a dedicated process. However,
  // the converse does not hold: this might still return false for certain
  // special cases where a site specific process lock can't be applied even when
  // this SiteInfo requires a dedicated process (e.g., with
  // --site-per-process). Examples of those cases include <webview> guests,
  // single-process mode, or extensions where a process is currently allowed to
  // be reused for different extensions.  Most of these special cases should
  // eventually be removed, and this function should become equivalent to
  // RequiresDedicatedProcess().
  bool ShouldLockProcessToSite(const IsolationContext& isolation_context) const;

  // Returns whether the process-per-site model is in use (globally or just for
  // the current site), in which case we should ensure there is only one
  // RenderProcessHost per site for the entire browser context.
  bool ShouldUseProcessPerSite(BrowserContext* browser_context) const;

  // Write a representation of this object into a trace.
  void WriteIntoTrace(perfetto::TracedValue context) const;

 private:
  // Helper that returns a tuple of all the fields that are relevant for
  // comparing one SiteInfo to another, to tell whether they represent the same
  // underlying security principal.   This determines the SiteInfo's key for
  // containers; two SiteInfos that return the same value here will map to the
  // same entry in std::map, etc.
  static auto MakeSecurityPrincipalKey(const SiteInfo& site_info);

  // Returns the AgentClusterKey (and OAC status) appropriate to use for the
  // provided |url_info|. |effective_url| is the effective URL, which can
  // override the real URL in |url_info| when loading hosted apps or the NTP. If
  // an |effective_url| is provided, the AgentClusterKey will be computed based
  // on this effective URL rather than the real URL. The |effective_url| is
  // expected to be different from the real URL, except in the case of WebUIs
  // (see below).
  //
  // Note: in the case of WebUIs, this function should first be called without
  // an |effective_url| to compute the AgentClusterKey, and with an
  // |effective_url| which is the real URL of the WebUI. The first call will
  // return an AgentClusterKey whose site URL is the TLD (ie chrome://bar). The
  // second call will be used to compute a Site URL which is the WebUIType. This
  // allows WebUI to continue to differentiate WebUIType via SiteURL while
  // allowing WebUI with a shared TLD to share a RenderProcessHost.
  // TODO(crbug.com/40176090): Remove this and replace it with
  // SiteInstanceGroups once the support lands.
  static AgentClusterKey GetAgentClusterKeyForURL(
      const IsolationContext& isolation_context,
      const UrlInfo& url_info,
      std::optional<GURL> effective_url);

  // The following functions are helpers for GetAgentClusterKeyForURL that
  // covers the various fetch and local schemes.
  static AgentClusterKey GetAgentClusterKeyForNonOpaqueOrigin(
      const IsolationContext& isolation_context,
      const UrlInfo& url_info,
      const url::Origin& origin,
      const OriginAgentClusterIsolationState& oac_isolation_state,
      bool is_origin_isolated_sandboxed_data_iframe);
  static AgentClusterKey GetAgentClusterKeyForSchemeOnlyOrigin(
      const UrlInfo& url_info,
      const url::Origin& origin,
      AgentClusterKey::OACStatus oac_status);
  static AgentClusterKey GetAgentClusterKeyForDataURL(
      const UrlInfo& url_info,
      const url::Origin& origin,
      AgentClusterKey::OACStatus oac_status);
  static AgentClusterKey GetAgentClusterKeyForBlobURL(
      const GURL& url,
      AgentClusterKey::OACStatus oac_status);

  // Helper function for ProcessLockCompareTo(). Returns a std::tie of the
  // SiteInfo elements required for doing a ProcessLock comparison.
  auto MakeProcessLockComparisonKey() const;

  // In some cases such as hosted apps, the URL or origin of the AgentClusterKey
  // might be overridden by an effective URL. The overridden site URL is stored
  // in this member. When there is no effective URL, |site_url_| simply
  // duplicates the information returned by GetProcessLockURL(). Regardless of
  // the presence of effective URLs, it is never used when assigning a process
  // lock. When assigning a process lock, we only take into account the
  // AgentClusterKey.
  GURL site_url_;

  // The AgentClusterKey for the execution context. This represents the
  // set of contexts that has synchronous access to each other and must be
  // placed in the same process.
  // TODO(crbug.com/342365083): Documents crossOriginIsolated through the use of
  // COOP and COEP should also use the AgentClusterKey instead of
  // WebExposedIsolationInfo.
  AgentClusterKey agent_cluster_key_;

  // When true, indicates this SiteInfo is for a origin-restricted-sandboxed
  // iframe.
  bool is_sandboxed_ = false;

  // When kIsolateSandboxedIframes is active using per-document grouping, each
  // isolated frame gets its own SiteInfo with a unique document identifier,
  // which in practice is the `navigation_id` for the NavigationRequest that led
  // to the creation of the SiteInstance. This value will be used in comparing
  // SiteInfos unless it is kInvalidUniqueSandboxId. It should be noted that the
  // value of `unique_sandbox_id_` will change for any cross-document
  // navigation, even if it's same-origin and/or stays in the same
  // RenderFrameHost.
  int unique_sandbox_id_;

  // The StoragePartitionConfig to use when loading content belonging to this
  // SiteInfo.
  StoragePartitionConfig storage_partition_config_;

  // Indicates the web-exposed isolation mode of the BrowsingInstance that
  // agents with this SiteInfo belongs to. The level of isolation which a page
  // opts-into has implications for the set of other pages which can live in
  // this SiteInstance, process allocation decisions, and API exposure in the
  // page's JavaScript context.
  WebExposedIsolationInfo web_exposed_isolation_info_ =
      WebExposedIsolationInfo::CreateNonIsolated();

  // Indicates the web-exposed isolation capability of agents with this
  // SiteInfo, ignoring the 'cross-origin-isolated' permissions policy. This is
  // a function of `web_exposed_isolation_info_` and the origins belonging to
  // this SiteInstance.
  //
  // This may be a lower isolation level than `web_exposed_isolation_info_`
  // because "Isolated Application" cannot be delegated cross-origin.
  WebExposedIsolationLevel web_exposed_isolation_level_ =
      WebExposedIsolationLevel::kNotIsolated;

  // Indicates this SiteInfo is for a <webview> guest.
  bool is_guest_ = false;

  // Indicates that there is a request to require a dedicated process for this
  // SiteInfo due to a hint from the Cross-Origin-Opener-Policy header.
  bool does_site_request_dedicated_process_for_coop_ = false;

  // Indicates that JIT is disabled for this SiteInfo.
  bool is_jit_disabled_ = false;

  // Indicates that v8 optimizations are disabled for this SiteInfo.
  bool are_v8_optimizations_disabled_ = false;

  // Indicates that this SiteInfo is for content inside a fenced frame. We use
  // just a bool as opposed to a GUID here in order to group same-origin fenced
  // frames together. See more details around fenced frame process isolation
  // here:
  // https://github.com/WICG/fenced-frame/blob/master/explainer/process_isolation.md.
  bool is_fenced_ = false;

  // Unique id of the BrowserContext. SiteInfos associated with different
  // BrowserContexts should be considered distinct security principals.
  base::UnguessableToken browser_context_id_;

  // Embedder-specified process isolation policy for this SiteInfo. See
  // //content/browser/embedder_isolation_info.h.
  EmbedderIsolationInfo embedder_isolation_info_ =
      EmbedderIsolationInfo::CreateNone();
};

CONTENT_EXPORT std::ostream& operator<<(std::ostream& out,
                                        const SiteInfo& site_info);

}  // namespace content

#endif  // CONTENT_BROWSER_SITE_INFO_H_