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

content/browser/frame_host/render_frame_host_manager.h

Index: content/browser/frame_host/render_frame_host_manager.h
diff --git a/content/browser/frame_host/render_frame_host_manager.h b/content/browser/frame_host/render_frame_host_manager.h
index af88aa5ccf2674c3b2dab2213a7483dde36e62a7..9c7fcd38559e91c00073c2c728711319696a5622 100644
--- a/content/browser/frame_host/render_frame_host_manager.h
+++ b/content/browser/frame_host/render_frame_host_manager.h
@@ -175,6 +175,11 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
     // hidden state.
     virtual bool IsHidden() = 0;
 
+    // Returns the FTN id of the outer WebContents that is hosting this

[nasko, 2015/05/22 16:32:27]

nit: s/FTN/FrameTreeNode/

[lazyboy, 2015/05/26 16:32:54]

Done.

+    // (inner) WebContents.
+    // Returns -1 if this WebContents does not have an outer WebContents.
+    virtual int GetOuterWebContentsFrameTreeNodeID() = 0;

[nasko, 2015/05/22 16:32:27]

At this layer (content/browser/frame_host) we don't know of WebContents, which
is why we have this delegate. I don't know if it is a good idea to put that
object type in the name of the method. Unfortunately, I don't have a good
suggestion on what will work better : (. Maybe GetContainerFrameTreeNodeID,
since you used that terminology in the WebContents layer?

[Charlie Reis, 2015/05/22 23:44:31]

In a sense, "delegate" refers to WebContents, so maybe
GetOuterDelegateFrameTreeNodeID?

[lazyboy, 2015/05/26 16:32:54]

Using GetOuterDelegateFrameTreeNodeID.

+
    protected:
     virtual ~Delegate() {}
   };
@@ -221,6 +226,14 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   RenderWidgetHostView* GetRenderWidgetHostView() const;
 
   RenderFrameProxyHost* GetProxyToParent();
+  RenderFrameProxyHost* GetProxyToOuterContents();

[nasko, 2015/05/22 16:32:27]

nit: Similar issue with Contents as above. This layer doesn't know what embeds
it.

[Charlie Reis, 2015/05/22 23:44:30]

GetProxyToOuterDelegate?

[lazyboy, 2015/05/26 16:32:54]

Using GetProxyToOuterDelegate().
Done.

+
+  // Returns whether this manager belongs to a FTN that is a main frame in

[nasko, 2015/05/22 16:32:27]

nit: s/FTN/FrameTreeNode/

[lazyboy, 2015/05/26 16:32:54]

Done.

+  // an inner WebContents.
+  //
+  // TODO(lazyboy): Make this work correctly for subframes inside inner
+  // WebContents too.
+  bool IsGuest();

[Charlie Reis, 2015/05/22 23:44:30]

ForInnerDelegate?

I'm ok with mentioning "inner WebContents" in the comment, just not the method
name.  We should also avoid guest/embedder.

[lazyboy, 2015/05/26 16:32:54]

Done.

 
   // Returns the pending RenderFrameHost, or NULL if there is no pending one.
   RenderFrameHostImpl* pending_frame_host() const {
@@ -414,6 +427,19 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
                                    RenderViewHostImpl* render_view_host,
                                    SiteInstance* instance);
 
+  // Called on the RFHM of the inner WebContents to create a proxy for this
+  // inner WebContents' frame in its outer WebContents' process.

[Charlie Reis, 2015/05/22 23:44:30]

nit: WebContents's

(Always use 's when the noun is singular, even when it ends in s.  In this case,
WebContents is singular.)

[lazyboy, 2015/05/26 16:32:54]

Done.

+  // Returns the proxy routing ID.
+  int CreateOuterContentsProxy(SiteInstance* outer_contents_site_instance);

[nasko, 2015/05/22 16:32:27]

Can we avoid using "Contents" here? The method seems to just create a proxy
based on a SiteInstance. Does it do anything more special than
CreateRenderFrameProxy?

[Charlie Reis, 2015/05/22 23:44:30]

CreateOuterDelegateProxy(SiteInstance* outer_site_instance)?

[lazyboy, 2015/05/26 16:32:54]

Done.
 The method seems to just create a proxy based on a SiteInstance. Does it do
anything more special than CreateRenderFrameProxy?

As you've noted in the .cc file, we need to create swapped
out RV and RF as well to create the proxy.
I've added a todo on the caller to use CreateRenderFrameProxy
once we can create proxies w/o swapped out. Bug #? I can add a reference to
that.

+
+  // Called on the RFHM of outer WebContents to replace the initial frame in the
+  // outer WebContents with the proxy that has routing id
+  // |proxy_to_outer_contents_routing_id|.
+  void ReplaceWithInnerContentsProxy(int proxy_to_outer_contents_routing_id);

[nasko, 2015/05/22 16:32:27]

Maybe named "SwapFrameWithProxy"? Those are all basic operations that we can
perform even without inner/outer WebContents, so having those be more generic
names allows us to reuse them if needed. Also, the comments about how
WebContents are linked to each other belong in the WebContents code that invokes
those methods.

[lazyboy, 2015/05/26 16:32:54]

Done.
Also, the comments about how WebContents are linked to each other belong in the
WebContents code that invokes those methods.

Done, the caller already has comments.
We did this because we wanted to be explicit about how to use
this method, now that we've renamed to SwapFrameWithProxy,
and this is more generic to be used in other places, I think
removing the comment here makes sense.

+
+  // Sets the child RWHV for this frame that is part of an inner WebContents.
+  void SetRWHViewForInnerContents(RenderWidgetHostView* child_rwhv);
+
  private:
   friend class FrameTreeVisualizer;
   friend class NavigatorTestWithBrowserSideNavigation;