Make code path for bounds changes getting to renderer less brittle

content/browser/web_contents/web_contents_view_aura.cc

Index: content/browser/web_contents/web_contents_view_aura.cc
diff --git a/content/browser/web_contents/web_contents_view_aura.cc b/content/browser/web_contents/web_contents_view_aura.cc
index 3f520db8d6efc07e5558fa6a1d2e21adfa794c28..b0beaa2864e4021cd95ecbcb9c83b78a138ec17c 100644
--- a/content/browser/web_contents/web_contents_view_aura.cc
+++ b/content/browser/web_contents/web_contents_view_aura.cc
@@ -43,9 +43,7 @@
 #include "ui/aura/client/window_tree_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/root_window_observer.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_observer.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/custom_data_helper.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
@@ -648,75 +646,6 @@ class OverscrollNavigationOverlay :
   DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
 };
 
-class WebContentsViewAura::WindowObserver
-    : public aura::WindowObserver, public aura::RootWindowObserver {
- public:
-  explicit WindowObserver(WebContentsViewAura* view)
-      : view_(view),
-        parent_(NULL) {
-    view_->window_->AddObserver(this);
-  }
-
-  virtual ~WindowObserver() {
-    view_->window_->RemoveObserver(this);
-    if (view_->window_->GetDispatcher())
-      view_->window_->GetDispatcher()->RemoveRootWindowObserver(this);
-    if (parent_)
-      parent_->RemoveObserver(this);
-  }
-
-  // Overridden from aura::WindowObserver:
-  virtual void OnWindowParentChanged(aura::Window* window,
-                                     aura::Window* parent) OVERRIDE {
-    if (window == parent_)
-      return;
-    if (parent_)
-      parent_->RemoveObserver(this);
-    parent_ = parent;
-    if (parent)
-      parent->AddObserver(this);
-  }
-
-  virtual void OnWindowBoundsChanged(aura::Window* window,
-                                     const gfx::Rect& old_bounds,
-                                     const gfx::Rect& new_bounds) OVERRIDE {
-    SendScreenRects();
-    if (view_->touch_editable_)
-      view_->touch_editable_->UpdateEditingController();
-  }
-
-  virtual void OnWindowAddedToRootWindow(aura::Window* window) OVERRIDE {
-    if (window != parent_)
-      window->GetDispatcher()->AddRootWindowObserver(this);
-  }
-
-  virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE {
-    if (window != parent_)
-      window->GetDispatcher()->RemoveRootWindowObserver(this);
-  }
-
-  // Overridden RootWindowObserver:
-  virtual void OnRootWindowHostMoved(const aura::RootWindow* root,
-                                     const gfx::Point& new_origin) OVERRIDE {
-    // This is for the desktop case (i.e. Aura desktop).
-    SendScreenRects();
-  }
-
- private:
-  void SendScreenRects() {
-    RenderWidgetHostImpl::From(view_->web_contents_->GetRenderViewHost())->
-        SendScreenRects();
-  }
-
-  WebContentsViewAura* view_;
-
-  // We cache the old parent so that we can unregister when it's not the parent
-  // anymore.
-  aura::Window* parent_;
-
-  DISALLOW_COPY_AND_ASSIGN(WindowObserver);
-};
-
 #if defined(OS_WIN)
 // Constrained windows are added as children of the WebContent's view which may
 // overlap with windowed NPAPI plugins. In that case, tell the RWHV so that it
@@ -831,7 +760,7 @@ WebContentsViewAura::~WebContentsViewAura() {
   if (!window_)
     return;
 
-  window_observer_.reset();
+  bounds_observer_.reset();
 #if defined(OS_WIN)
   child_window_observer_.reset();
 #endif
@@ -1164,7 +1093,8 @@ void WebContentsViewAura::CreateView(
   window_->layer()->SetMasksToBounds(true);
   window_->SetName("WebContentsViewAura");
 
-  window_observer_.reset(new WindowObserver(this));
+  bounds_observer_.reset(new NativeViewScreenBoundsObserver());
+  bounds_observer_->Init(this);
 #if defined(OS_WIN)
   child_window_observer_.reset(new ChildWindowObserver(this));
 #endif
@@ -1652,4 +1582,45 @@ int WebContentsViewAura::OnPerformDrop(const ui::DropTargetEvent& event) {
   return current_drag_op_;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// WebContentsViewAura, WebContentsViewAuraWindowObserverDelgate implementation:
+
+aura::Window* WebContentsViewAura::GetDelegateWindow() {
+  return window_.get();
+}
+
+void WebContentsViewAura::AddDelegateWindowObserver(
+    aura::WindowObserver* observer) {
+  window_->AddObserver(observer);
+}
+
+void WebContentsViewAura::RemoveDelegateWindowObserver(
+    aura::WindowObserver* observer) {
+    window_->RemoveObserver(observer);
+}
+
+void WebContentsViewAura::RemoveRootWindowObserver(
+    aura::RootWindowObserver* observer) {
+  if (window_->GetDispatcher())
+    window_->GetDispatcher()->RemoveRootWindowObserver(observer);
+}
+
+void WebContentsViewAura::AddRootWindowObserver(
+    aura::RootWindowObserver* observer) {
+  if (window_->GetDispatcher())
+    window_->GetDispatcher()->AddRootWindowObserver(observer);
+}
+
+void WebContentsViewAura::OnScreenPositionChanged() {
+  RenderWidgetHostImpl::From(web_contents_->GetRenderViewHost())->
+      SendScreenRects();
+}
+
+void WebContentsViewAura::OnScreenBoundsChanged() {
+  RenderWidgetHostImpl::From(web_contents_->GetRenderViewHost())->
+      SendScreenRects();
+  if (touch_editable_)
+    touch_editable_->UpdateEditingController();
+}
+
 }  // namespace content