Plumb ViewportMetrics change notifications around the world and back.

services/view_manager/view_manager_service_impl.cc

 // Copyright 2014 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.
 
 #include "services/view_manager/view_manager_service_impl.h"
 
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/converters/input_events/input_events_type_converters.h"
@@ skipping 157 matching lines @@
     const gfx::Rect& old_bounds,
     const gfx::Rect& new_bounds,
     bool originated_change) {
   if (originated_change || !IsViewKnown(view))
     return;
   client()->OnViewBoundsChanged(ViewIdToTransportId(view->id()),
                                 Rect::From(old_bounds),
                                 Rect::From(new_bounds));
 }
 
+void ViewManagerServiceImpl::ProcessViewportMetricsChanged(
+    const ServerView* view,
+    const mojo::ViewportMetrics& old_metrics,
+    const mojo::ViewportMetrics& new_metrics,
+    bool originated_change) {
+  if (originated_change || !IsViewKnown(view))

[sky, 2015/01/27 16:35:08]

This is only going to notify clients that know of |view|. As metrics are
inherited you need to notify everyone. I would notify each connection using the
connections root (don't notify if the connection doesn't have a root), eg:

if (!root())
  return;

client()->OnViewViewportMetricsChanged(ViewIdToTransportId(*root());

And be sure and clarify in the mojom docs the client is only notified for it's
root.

[eseidel, 2015/01/27 18:50:04]

I just copied this from ProcessBoundsChanged. :/

+    return;
+  client()->OnViewViewportMetricsChanged(ViewIdToTransportId(view->id()),
+                                         old_metrics.Clone(),
+                                         new_metrics.Clone());
+}
+
 void ViewManagerServiceImpl::ProcessWillChangeViewHierarchy(
     const ServerView* view,
     const ServerView* new_parent,
     const ServerView* old_parent,
     bool originated_change) {
   if (originated_change)
     return;
 
   const bool old_drawn = view->IsDrawn(connection_manager_->root());
   const bool new_drawn = view->visible() && new_parent &&
@@ skipping 418 matching lines @@
 }
 
 bool ViewManagerServiceImpl::IsViewRootOfAnotherConnectionForAccessPolicy(
     const ServerView* view) const {
   ViewManagerServiceImpl* connection =
       connection_manager_->GetConnectionWithRoot(view->id());
   return connection && connection != this;
 }
 
 }  // namespace view_manager