Make <webview> use out-of-process iframe architecture.

content/browser/web_contents/web_contents_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 261 matching lines @@
   void SetIsCrashed(base::TerminationStatus status, int error_code) override;
   base::TerminationStatus GetCrashedStatus() const override;
   bool IsBeingDestroyed() const override;
   void NotifyNavigationStateChanged(InvalidateTypes changed_flags) override;
   base::TimeTicks GetLastActiveTime() const override;
   void SetLastActiveTime(base::TimeTicks last_active_time) override;
   void WasShown() override;
   void WasHidden() override;
   bool NeedToFireBeforeUnload() override;
   void DispatchBeforeUnload(bool for_cross_site_transition) override;
+  void AttachToOuterWebContentsFrame(
+      WebContents* outer_web_contents,
+      RenderFrameHost* outer_contents_frame) override;
   void Stop() override;
   WebContents* Clone() override;
   void ReloadFocusedFrame(bool ignore_cache) override;
   void Undo() override;
   void Redo() override;
   void Cut() override;
   void Copy() override;
   void CopyToFindPboard() override;
   void Paste() override;
   void PasteAndMatchStyle() override;
@@ skipping 295 matching lines @@
   void NotifyMainFrameSwappedFromRenderManager(
       RenderViewHost* old_host,
       RenderViewHost* new_host) override;
   int CreateOpenerRenderViewsForRenderManager(SiteInstance* instance) override;
   NavigationControllerImpl& GetControllerForRenderManager() override;
   scoped_ptr<WebUIImpl> CreateWebUIForRenderManager(const GURL& url) override;
   NavigationEntry* GetLastCommittedNavigationEntryForRenderManager() override;
   bool FocusLocationBarByDefault() override;
   void SetFocusToLocationBar(bool select_all) override;
   bool IsHidden() override;
+  int GetOuterDelegateFrameTreeNodeID() override;
 
   // NotificationObserver ------------------------------------------------------
 
   void Observe(int type,
                const NotificationSource& source,
                const NotificationDetails& details) override;
 
   // NavigationControllerDelegate ----------------------------------------------
 
   WebContents* GetWebContents() override;
@@ skipping 111 matching lines @@
                            CrossSiteIframeAccessibility);
 
   // So InterstitialPageImpl can access SetIsLoading.
   friend class InterstitialPageImpl;
 
   // TODO(brettw) TestWebContents shouldn't exist!
   friend class TestWebContents;
 
   class DestructionObserver;
 
+  // Represents a WebContents node in a tree of WebContents structure.
+  //
+  // Two WebContents with separate FrameTrees can be connected by
+  // outer/inner relationship using this class. Note that their FrameTrees
+  // still remain disjoint.
+  // The parent is referred to as "outer WebContents" and the descendents are
+  // referred to as "inner WebContents".

[Charlie Reis, 2015/06/18 00:13:18]

Can you add a bit about whether the outer WebContents has a FrameTreeNode
corresponding to the inner WebContents or not?

[lazyboy, 2015/06/18 22:45:13]

Done.

+  struct WebContentsTreeNode {
+   public:
+    WebContentsTreeNode();
+    ~WebContentsTreeNode();
+
+    typedef std::set<WebContentsTreeNode*> ChildrenSet;
+
+    void ConnectToOuterWebContents(WebContentsImpl* outer_web_contents,
+                                   RenderFrameHostImpl* outer_contents_frame);
+
+    int outer_contents_frame_tree_node_id() {
+      return outer_contents_frame_tree_node_id_;
+    }
+    WebContentsImpl* outer_web_contents() { return outer_web_contents_; }
+
+   private:
+    int outer_contents_frame_tree_node_id_;

[Charlie Reis, 2015/06/18 00:13:19]

This should come after outer_web_contents_, since it's a reference to something
inside it.  

Also, please put comments on these members.

[lazyboy, 2015/06/18 22:45:13]

Done.

+    WebContentsImpl* outer_web_contents_;
+    ChildrenSet inner_web_contents_tree_nodes_;
+  };
+
   // See WebContents::Create for a description of these parameters.
   WebContentsImpl(BrowserContext* browser_context);
 
   // Add and remove observers for page navigation notifications. The order in
   // which notifications are sent to observers is undefined. Clients must be
   // sure to remove the observer before they go away.
   void AddObserver(WebContentsObserver* observer);
   void RemoveObserver(WebContentsObserver* observer);
 
   // Clears a pending contents that has been closed before being shown.
@@ skipping 291 matching lines @@
   scoped_ptr<PowerSaveBlocker> video_power_save_blocker_;
 
   // Tells whether this WebContents is actively producing sound.
   // Order is important: the |frame_tree_| destruction uses
   // |audio_state_provider_|.
   scoped_ptr<AudioStateProvider> audio_state_provider_;
 
   // Manages the frame tree of the page and process swaps in each node.
   FrameTree frame_tree_;
 
+  // If this WebContents is part of a "tree of WebContents", then this contains
+  // information about the structure.
+  scoped_ptr<WebContentsTreeNode> node_;
+
   // SavePackage, lazily created.
   scoped_refptr<SavePackage> save_package_;
 
   // Data for loading state ----------------------------------------------------
 
   // Indicates whether we're currently loading a resource.
   bool is_loading_;
 
   // Indicates whether the current load is to a different document. Only valid
   // if is_loading_ is true.
@@ skipping 226 matching lines @@
   // Adds/removes a callback called on creation of each new WebContents.
   static void AddCreatedCallbackForTesting(const CreatedCallback& callback);
   static void RemoveCreatedCallbackForTesting(const CreatedCallback& callback);
 
   DISALLOW_COPY_AND_ASSIGN(FriendZone);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_