Revert of Snap RWHVA and resize the legacy window on Windows whenever the ancestor window's bounds change.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index bd7e516724a66502668348c5e67b2c38d897e1d0..146355707f08f247446929d5c6c0d22d7b5e11e2 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -3,8 +3,6 @@
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
-
-#include <set>
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
@@ -354,62 +352,10 @@
       view_->RemovingFromRootWindow();
   }
 
-  void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override {
-    view_->ParentHierarchyChanged();
-  }
-
  private:
   RenderWidgetHostViewAura* view_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowObserver);
-};
-
-// This class provides functionality to observe the ancestors of the RWHVA for
-// bounds changes. This is done to snap the RWHVA window to a pixel boundary,
-// which could change when the bounds relative to the root changes.
-// An example where this happens is below:-
-// The fast resize code path for bookmarks where in the parent of RWHVA which
-// is WCV has its bounds changed before the bookmark is hidden. This results in
-// the traditional bounds change notification for the WCV reporting the old
-// bounds as the bookmark is still around. Observing all the ancestors of the
-// RWHVA window enables us to know when the bounds of the window relative to
-// root changes and allows us to snap accordingly.
-class RenderWidgetHostViewAura::WindowAncestorObserver
-    : public aura::WindowObserver {
- public:
-  explicit WindowAncestorObserver(RenderWidgetHostViewAura* view)
-      : view_(view) {
-    aura::Window* parent = view_->window_->parent();
-    while (parent) {
-      parent->AddObserver(this);
-      ancestors_.insert(parent);
-      parent = parent->parent();
-    }
-  }
-
-  ~WindowAncestorObserver() override {
-    RemoveAncestorObservers();
-  }
-
-  void OnWindowBoundsChanged(aura::Window* window,
-                             const gfx::Rect& old_bounds,
-                             const gfx::Rect& new_bounds) override {
-    DCHECK(ancestors_.find(window) != ancestors_.end());
-    if (new_bounds.origin() != old_bounds.origin())
-      view_->HandleParentBoundsChanged();
-  }
-
- private:
-  void RemoveAncestorObservers() {
-    for (auto ancestor : ancestors_)
-      ancestor->RemoveObserver(this);
-    ancestors_.clear();
-  }
-
-  RenderWidgetHostViewAura* view_;
-  std::set<aura::Window*> ancestors_;
-
-  DISALLOW_COPY_AND_ASSIGN(WindowAncestorObserver);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -449,7 +395,6 @@
     host_->SetView(this);
 
   window_observer_.reset(new WindowObserver(this));
-
   aura::client::SetTooltipText(window_, &tooltip_);
   aura::client::SetActivationDelegate(window_, this);
   aura::client::SetFocusChangeObserver(window_, this);
@@ -789,22 +734,6 @@
   return true;
 }
 
-void RenderWidgetHostViewAura::HandleParentBoundsChanged() {
-  SnapToPhysicalPixelBoundary();
-#if defined(OS_WIN)
-  if (legacy_render_widget_host_HWND_) {
-    legacy_render_widget_host_HWND_->SetBounds(
-        window_->GetBoundsInRootWindow());
-  }
-#endif
-}
-
-void RenderWidgetHostViewAura::ParentHierarchyChanged() {
-  ancestor_window_observer_.reset(new WindowAncestorObserver(this));
-  // Snap when we receive a hierarchy changed. http://crbug.com/388908.
-  HandleParentBoundsChanged();
-}
-
 void RenderWidgetHostViewAura::MovePluginWindows(
     const std::vector<WebPluginGeometry>& plugin_window_moves) {
 #if defined(OS_WIN)