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 353da78864c40635ea53147d97a438323e815ceb..e761f51758b0878561eda374afbc2d0e14275645 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"
@@ -648,239 +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);
-
-#if defined(OS_WIN)
-    if (view_->window_->GetRootWindow())
-      view_->window_->GetRootWindow()->AddObserver(this);
-#endif
-  }
-
-  virtual ~WindowObserver() {
-    view_->window_->RemoveObserver(this);
-    if (view_->window_->GetDispatcher())
-      view_->window_->GetDispatcher()->RemoveRootWindowObserver(this);
-    if (parent_)
-      parent_->RemoveObserver(this);
-
-#if defined(OS_WIN)
-    if (parent_) {
-      const aura::Window::Windows& children = parent_->children();
-      for (size_t i = 0; i < children.size(); ++i)
-        children[i]->RemoveObserver(this);
-    }
-
-    aura::Window* root_window = view_->window_->GetRootWindow();
-    if (root_window) {
-      root_window->RemoveObserver(this);
-      const aura::Window::Windows& root_children = root_window->children();
-      for (size_t i = 0; i < root_children.size(); ++i)
-        root_children[i]->RemoveObserver(this);
-    }
-#endif
-  }
-
-  // Overridden from aura::WindowObserver:
-#if defined(OS_WIN)
-  // Constrained windows are added as children of the parent's parent's view
-  // which may overlap with windowed NPAPI plugins. In that case, tell the RWHV
-  // so that it can update the plugins' cutout rects accordingly.
-  // Note: this is hard coding how Chrome layer adds its dialogs. Since NPAPI is
-  // going to be deprecated in a year, this is ok for now. The test for this is
-  // PrintPreviewTest.WindowedNPAPIPluginHidden.
-  virtual void OnWindowAdded(aura::Window* new_window) OVERRIDE {
-    if (new_window == view_->window_)
-      return;
-
-    if (new_window == parent_)
-      return;  // This happens if the parent moves to the root window.
-
-    // Observe sibling windows of the WebContents, or children of the root
-    // window.
-    if (new_window->parent() == parent_ ||
-        new_window->parent() == view_->window_->GetRootWindow()) {
-      new_window->AddObserver(this);
-      UpdateConstrainedWindows(NULL);
-    }
-  }
-
-  virtual void OnWillRemoveWindow(aura::Window* window) OVERRIDE {
-    if (window == view_->window_)
-      return;
-
-    window->RemoveObserver(this);
-    UpdateConstrainedWindows(window);
-  }
-
-  virtual void OnWindowVisibilityChanged(aura::Window* window,
-                                         bool visible) OVERRIDE {
-    if (window == view_->window_)
-      return;
-
-    if (window->parent() == parent_ ||
-        window->parent() == view_->window_->GetRootWindow()) {
-      UpdateConstrainedWindows(NULL);
-    }
-  }
-#endif
-
-  virtual void OnWindowParentChanged(aura::Window* window,
-                                     aura::Window* parent) OVERRIDE {
-    if (window != view_->window_)
-      return;
-    if (parent_)
-      parent_->RemoveObserver(this);
-
-#if defined(OS_WIN)
-    if (parent_) {
-      const aura::Window::Windows& children = parent_->children();
-      for (size_t i = 0; i < children.size(); ++i)
-        children[i]->RemoveObserver(this);
-
-      RenderWidgetHostViewAura* view = ToRenderWidgetHostViewAura(
-          view_->web_contents_->GetRenderWidgetHostView());
-      if (view)
-        view->UpdateConstrainedWindowRects(std::vector<gfx::Rect>());
-    }
-
-    // When we get parented to the root window, the code below will watch the
-    // parent, aka root window. Since we already watch the root window on
-    // Windows, unregister first so that the debug check doesn't fire.
-    if (parent && parent == window->GetRootWindow())
-      parent->RemoveObserver(this);
-
-    // We need to undo the above if we were parented to the root window and then
-    // got parented to another window. At that point, the code before the ifdef
-    // would have stopped watching the root window.
-    if (window->GetRootWindow() &&
-        parent != window->GetRootWindow() &&
-        !window->GetRootWindow()->HasObserver(this)) {
-      window->GetRootWindow()->AddObserver(this);
-    }
-#endif
-
-    parent_ = parent;
-    if (parent) {
-      parent->AddObserver(this);
-#if defined(OS_WIN)
-      if (parent != window->GetRootWindow()) {
-        const aura::Window::Windows& children = parent->children();
-        for (size_t i = 0; i < children.size(); ++i) {
-          if (children[i] != view_->window_)
-            children[i]->AddObserver(this);
-        }
-      }
-#endif
-    }
-  }
-
-  virtual void OnWindowBoundsChanged(aura::Window* window,
-                                     const gfx::Rect& old_bounds,
-                                     const gfx::Rect& new_bounds) OVERRIDE {
-    if (window == parent_ || window == view_->window_) {
-      SendScreenRects();
-      if (view_->touch_editable_)
-        view_->touch_editable_->UpdateEditingController();
-#if defined(OS_WIN)
-    } else {
-      UpdateConstrainedWindows(NULL);
-#endif
-    }
-  }
-
-  virtual void OnWindowAddedToRootWindow(aura::Window* window) OVERRIDE {
-    if (window == view_->window_) {
-      window->GetDispatcher()->AddRootWindowObserver(this);
-#if defined(OS_WIN)
-      if (!window->GetRootWindow()->HasObserver(this))
-        window->GetRootWindow()->AddObserver(this);
-#endif
-    }
-  }
-
-  virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE {
-    if (window == view_->window_) {
-      window->GetDispatcher()->RemoveRootWindowObserver(this);
-#if defined(OS_WIN)
-      window->GetRootWindow()->RemoveObserver(this);
-
-      const aura::Window::Windows& root_children =
-          window->GetRootWindow()->children();
-      for (size_t i = 0; i < root_children.size(); ++i) {
-        if (root_children[i] != view_->window_ && root_children[i] != parent_)
-          root_children[i]->RemoveObserver(this);
-      }
-#endif
-    }
-  }
-
-  // Overridden RootWindowObserver:
-  virtual void OnRootWindowHostMoved(const aura::RootWindow* root,
-                                     const gfx::Point& new_origin) OVERRIDE {
-    TRACE_EVENT1("ui",
-                 "WebContentsViewAura::WindowObserver::OnRootWindowHostMoved",
-                 "new_origin", new_origin.ToString());
-
-    // This is for the desktop case (i.e. Aura desktop).
-    SendScreenRects();
-  }
-
- private:
-  void SendScreenRects() {
-    RenderWidgetHostImpl::From(view_->web_contents_->GetRenderViewHost())->
-        SendScreenRects();
-  }
-
-#if defined(OS_WIN)
-  void UpdateConstrainedWindows(aura::Window* exclude) {
-    RenderWidgetHostViewAura* view = ToRenderWidgetHostViewAura(
-        view_->web_contents_->GetRenderWidgetHostView());
-    if (!view)
-      return;
-
-    std::vector<gfx::Rect> constrained_windows;
-    if (parent_) {
-      const aura::Window::Windows& children = parent_->children();
-      for (size_t i = 0; i < children.size(); ++i) {
-        if (children[i] != view_->window_ &&
-            children[i] != exclude &&
-            children[i]->IsVisible()) {
-          constrained_windows.push_back(children[i]->GetBoundsInRootWindow());
-        }
-      }
-    }
-
-    aura::Window* root_window = view_->window_->GetRootWindow();
-    const aura::Window::Windows& root_children = root_window->children();
-    if (root_window) {
-      for (size_t i = 0; i < root_children.size(); ++i) {
-        if (root_children[i]->IsVisible() &&
-            !root_children[i]->Contains(view_->window_.get())) {
-          constrained_windows.push_back(
-              root_children[i]->GetBoundsInRootWindow());
-        }
-      }
-    }
-
-    view->UpdateConstrainedWindowRects(constrained_windows);
-  }
-#endif
-
-  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);
-};
-
 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsViewAura, public:
 
@@ -905,7 +670,10 @@ WebContentsViewAura::~WebContentsViewAura() {
   if (!window_)
     return;
 
-  window_observer_.reset();
+  bounds_observer_.reset();
+#if defined(OS_WIN)
+  constrained_observer_.reset();
+#endif
 
   // Window needs a valid delegate during its destructor, so we explicitly
   // delete it here.
@@ -1236,13 +1004,18 @@ void WebContentsViewAura::CreateView(
   window_->layer()->SetMasksToBounds(true);
   window_->SetName("WebContentsViewAura");
 
-  // WindowObserver is not interesting and is problematic for Browser Plugin
+  // The observers are not interesting and is problematic for Browser Plugin
   // guests.
-  // The use cases for WindowObserver do not apply to Browser Plugins:
+  // The use cases for the observers do not apply to Browser Plugins:
   // 1) guests do not support NPAPI plugins.
   // 2) guests' window bounds are supposed to come from its embedder.
-  if (!web_contents_->GetRenderProcessHost()->IsGuest())
-    window_observer_.reset(new WindowObserver(this));
+  if (!web_contents_->GetRenderProcessHost()->IsGuest()) {
+    bounds_observer_.reset(new NativeViewScreenBoundsObserver(this,
+                                                              window_.get()));
+#if defined(OS_WIN)
+    constrained_observer_.reset(new ConstrainedWindowsObserver(this));
+#endif
+  }
 
   // delegate_->GetDragDestDelegate() creates a new delegate on every call.
   // Hence, we save a reference to it locally. Similar model is used on other
@@ -1727,4 +1500,19 @@ int WebContentsViewAura::OnPerformDrop(const ui::DropTargetEvent& event) {
   return current_drag_op_;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// WebContentsViewAura, NativeViewScreenBoundsObserverDelegate implementation:
+
+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