Navigation transitions: Block first response until after transitions have run.

content/public/browser/web_contents_observer.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_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 
 #include "base/process/kill.h"
 #include "base/process/process_handle.h"
 #include "content/common/content_export.h"
@@ skipping 228 matching lines @@
 
   // This method is invoked when the renderer has completed its first paint
   // after a non-empty layout.
   virtual void DidFirstVisuallyNonEmptyPaint() {}
 
   // These two methods correspond to the points in time when the spinner of the
   // tab starts and stops spinning.
   virtual void DidStartLoading(RenderViewHost* render_view_host) {}
   virtual void DidStopLoading(RenderViewHost* render_view_host) {}
 
+  // This method is invoked when the request is deferred immediately after
+  // receiving response headers.
+  virtual void DidDeferAfterResponseStarted() {}

[jam, 2014/06/10 05:54:56]

similarly, since this notification is only consumed inside content, no need to
add this to the public WebContentsObserver. have the code which calls this
callback instead call the one impl of this directly

[shatch, 2014/06/10 20:20:24]

I thought this was needed this to make its way to the java
WebContentsObserverAndroid so that the transition helper can listen for the
event. This gets sent through
RenderFrameHostImpl->WebContentsImpl->WebContentsObserverAndroid->java. Is there
another way to do that?

[jam, 2014/06/11 02:00:21]

WebContentsImpl can call the ContentViewCoreImpl method directly (getting it
through ContentViewCoreImpl::FromWebContents).

[shatch, 2014/06/14 00:41:37]

Ah great, thanks! Moved this to call ContentViewCoreImpl directly and
reimplemented the java side as a listener on ContentViewCore instead.

+
   // When WebContents::Stop() is called, the WebContents stops loading and then
   // invokes this method. If there are ongoing navigations, their respective
   // failure methods will also be invoked.
   virtual void NavigationStopped() {}
 
   // This indicates that the next navigation was triggered by a user gesture.
   virtual void DidGetUserGesture() {}
 
   // This method is invoked when a RenderViewHost of this WebContents was
   // configured to ignore UI events, and an UI event took place.
@@ skipping 106 matching lines @@
   void ResetWebContents();
 
   WebContentsImpl* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_