Make window.innerWidth and innerHeight cause layout if needed.

Source/core/frame/LocalDOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 927 matching lines @@
         return 0;
 
     FrameView* view = frame()->view();
     if (!view)
         return 0;
 
     FrameHost* host = frame()->host();
     if (!host)
         return 0;
 
+    // The main frame's innerHeight depends on the page scale. Since the initial
+    // page scale depends on the content width and is set after a layout,
+    // perform one now so queries before the first layout reflect the true size
+    // of the window.

[rune, 2015/04/16 22:02:12]

The initial scale can be adjusted multiple times after layout, afaict, so I
think you can delete "before the first layout".

[bokan, 2015/04/20 17:47:24]

Done.

+    if (host->settings().viewportEnabled() && frame()->isMainFrame())
+        frame()->document()->updateLayoutIgnorePendingStylesheets();
+
     // FIXME: This is potentially too much work. We really only need to know the dimensions of the parent frame's renderer.
     if (Frame* parent = frame()->tree().parent()) {
         if (parent && parent->isLocalFrame())
             toLocalFrame(parent)->document()->updateLayoutIgnorePendingStylesheets();
     }
 
     FloatSize viewportSize = frame()->isMainFrame()
         ? host->pinchViewport().visibleRect().size()
         : view->visibleContentRect(IncludeScrollbars).size();
 
     return adjustForAbsoluteZoom(expandedIntSize(viewportSize).height(), frame()->pageZoomFactor());
 }
 
 int LocalDOMWindow::innerWidth() const
 {
     if (!frame())
         return 0;
 
     FrameView* view = frame()->view();
     if (!view)
         return 0;
 
     FrameHost* host = frame()->host();
     if (!host)
         return 0;
 
+    // The main frame's innerHeight depends on the page scale. Since the initial
+    // page scale depends on the content width and is set after a layout,
+    // perform one now so queries before the first layout reflect the true size
+    // of the window.
+    if (host->settings().viewportEnabled() && frame()->isMainFrame())
+        frame()->document()->updateLayoutIgnorePendingStylesheets();
+

[rune, 2015/04/16 22:02:12]

Most code and comments in innerWidth and innerHeight are duplicated. How about
making a common method for returning the viewportSize and zoom-adjust the
correponding width/height value from it.

[bokan, 2015/04/20 17:47:24]

Done.

     // FIXME: This is potentially too much work. We really only need to know the dimensions of the parent frame's renderer.
     if (Frame* parent = frame()->tree().parent()) {
         if (parent && parent->isLocalFrame())
             toLocalFrame(parent)->document()->updateLayoutIgnorePendingStylesheets();
     }
 
     FloatSize viewportSize = frame()->isMainFrame()
         ? host->pinchViewport().visibleRect().size()
         : view->visibleContentRect(IncludeScrollbars).size();
 
@@ skipping 682 matching lines @@
     return m_frameObserver->frame();
 }
 
 v8::Handle<v8::Object> LocalDOMWindow::wrap(v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     ASSERT_NOT_REACHED(); // LocalDOMWindow has [Custom=ToV8].
     return v8::Handle<v8::Object>();
 }
 
 } // namespace blink