Send window frame information to Mac plugins via IPC

Sends any window frame and relevent content view location changes to the plugin process via IPC, so that the plugin process always knows where the plugin is rather than only knowing when the mouse is within the plugin area. This will be necessary for supporting NPN_ConvertPoint, and for supporting Java2 as currently implemented.

Related changes:
- Now that window information is being sent on init and un-hide, use that to get correct initial window focus information.
- Add a missing window focus change notification uncovered by the above.
- Use live mouse location for idle events, instead of a cached location, now that we have live plugin frame information.
- Refactor and simplify the logic for moving the plugin.

Note that containing_window_frame_ is currently unused, but will be shortly for NPN_ConvertPoint, and is so closely related to the added IPC that I added it now rather than having to immediately change the new messages and functions.

BUG=34046,31858,31543,29457
TEST=Mouse tracking in Carbon plugins should still work correctly, even across window moves, info/bookmark bar show/hides, etc. (Automated tests of location tracking will follow shortly with full NPN_ConvertPoint implementation.)

Review URL: http://codereview.chromium.org/573015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38361 0039d316-1c4b-4281-b951-d872f2087c98

15 files changed, 200 insertions, 19 deletions

diff --git a/chrome/browser/cocoa/browser_window_controller.mm b/chrome/browser/cocoa/browser_window_controller.mm
index ae59e2f..d7058e9 100644
--- a/chrome/browser/cocoa/browser_window_controller.mm
+++ b/chrome/browser/cocoa/browser_window_controller.mm
@@ -1701,6 +1701,12 @@ willPositionSheet:(NSWindow*)sheet
   if (statusBubble_) {
     statusBubble_->UpdateSizeAndPosition();
   }
+
+  // Let the selected RenderWidgetHostView know, so that it can tell plugins.
+  if (TabContents* contents = browser_->GetSelectedTabContents()) {
+    if (RenderWidgetHostView* rwhv = contents->render_widget_host_view())
+      rwhv->WindowFrameChanged();
+  }
 }
 
 // Handle the openLearnMoreAboutCrashLink: action from SadTabController when
@@ -1738,6 +1744,12 @@ willPositionSheet:(NSWindow*)sheet
       (windowTopGrowth_ > 0 && NSMinY(windowFrame) != NSMinY(workarea)) ||
       (windowBottomGrowth_ > 0 && NSMaxY(windowFrame) != NSMaxY(workarea)))
     [self resetWindowGrowthState];
+
+  // Let the selected RenderWidgetHostView know, so that it can tell plugins.
+  if (TabContents* contents = browser_->GetSelectedTabContents()) {
+    if (RenderWidgetHostView* rwhv = contents->render_widget_host_view())
+      rwhv->WindowFrameChanged();
+  }
 }
 
 // Delegate method called when window will be resized; not called for
@@ -2114,10 +2126,21 @@ willPositionSheet:(NSWindow*)sheet
                              width:(CGFloat)width {
   NSView* tabContentView = [self tabContentArea];
   NSRect tabContentFrame = [tabContentView frame];
+
+  bool contentShifted = NSMaxY(tabContentFrame) != maxY;
+
   tabContentFrame.origin.y = minY;
   tabContentFrame.size.height = maxY - minY;
   tabContentFrame.size.width = width;
   [tabContentView setFrame:tabContentFrame];
+
+  // If the relayout shifts the content area up or down, let the renderer know.
+  if (contentShifted) {
+    if (TabContents* contents = browser_->GetSelectedTabContents()) {
+      if (RenderWidgetHostView* rwhv = contents->render_widget_host_view())
+        rwhv->WindowFrameChanged();
+    }
+  }
 }
 
 - (BOOL)shouldShowBookmarkBar {
diff --git a/chrome/browser/renderer_host/render_widget_host_view.h b/chrome/browser/renderer_host/render_widget_host_view.h
index ccb1b31..f761053 100644
--- a/chrome/browser/renderer_host/render_widget_host_view.h
+++ b/chrome/browser/renderer_host/render_widget_host_view.h
@@ -171,6 +171,9 @@ class RenderWidgetHostView {
   // WasHidden/DidBecomeSelected.
   virtual void SetWindowVisibility(bool visible) = 0;
 
+  // Informs the view that its containing window's frame changed.
+  virtual void WindowFrameChanged() = 0;
+
   // Methods associated with GPU plugin instances
   virtual gfx::PluginWindowHandle AllocateFakePluginWindowHandle() = 0;
   virtual void DestroyFakePluginWindowHandle(
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.h b/chrome/browser/renderer_host/render_widget_host_view_mac.h
index c9834bf..c707205 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.h
@@ -46,6 +46,7 @@ class RWHVMEditCommandHelper;
   scoped_nsobject<NSString> toolTip_;
 
   scoped_nsobject<NSEvent> lastKeyPressedEvent_;
+  NSWindow* lastWindow_;  // weak
 }
 
 - (void)setCanBeKeyView:(BOOL)can;
@@ -112,6 +113,7 @@ class RenderWidgetHostViewMac : public RenderWidgetHostView {
   virtual gfx::Rect GetRootWindowRect();
   virtual void SetActive(bool active);
   virtual void SetWindowVisibility(bool visible);
+  virtual void WindowFrameChanged();
   virtual void SetBackground(const SkBitmap& background);
 
   // Methods associated with GPU plugin instances
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.mm b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
index db78a46..c804892 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
@@ -582,13 +582,20 @@ gfx::Rect RenderWidgetHostViewMac::GetWindowRect() {
   // TODO(shess): In case of !window, the view has been removed from
   // the view hierarchy because the tab isn't main.  Could retrieve
   // the information from the main tab for our window.
-  if (!cocoa_view_ || ![cocoa_view_ window]) {
+  NSWindow* enclosing_window = [cocoa_view_ window];
+  if (!cocoa_view_ || !enclosing_window) {
     return gfx::Rect();
   }
 
+  // During dragging of a torn-off tab, [cocoa_view_ window] is a floating panel
+  // attached to the actual browser window that the tab is visually part of; we
+  // want the bounds of the browser window rather than the panel.
+  if ([enclosing_window parentWindow])
+    enclosing_window = [enclosing_window parentWindow];
+
   NSRect bounds = [cocoa_view_ bounds];
   bounds = [cocoa_view_ convertRect:bounds toView:nil];
-  bounds.origin = [[cocoa_view_ window] convertBaseToScreen:bounds.origin];
+  bounds.origin = [enclosing_window convertBaseToScreen:bounds.origin];
   return NSRectToRect(bounds, [[cocoa_view_ window] screen]);
 }
 
@@ -596,12 +603,19 @@ gfx::Rect RenderWidgetHostViewMac::GetRootWindowRect() {
   // TODO(shess): In case of !window, the view has been removed from
   // the view hierarchy because the tab isn't main.  Could retrieve
   // the information from the main tab for our window.
-  if (!cocoa_view_ || ![cocoa_view_ window]) {
+  NSWindow* enclosing_window = [cocoa_view_ window];
+  if (!enclosing_window) {
     return gfx::Rect();
   }
 
-  NSRect bounds = [[cocoa_view_ window] frame];
-  return NSRectToRect(bounds, [[cocoa_view_ window] screen]);
+  // During dragging of a torn-off tab, [cocoa_view_ window] is a floating panel
+  // attached to the actual browser window that the tab is visually part of; we
+  // want the bounds of the browser window rather than the panel.
+  if ([enclosing_window parentWindow])
+    enclosing_window = [enclosing_window parentWindow];
+
+  NSRect bounds = [enclosing_window frame];
+  return NSRectToRect(bounds, [enclosing_window screen]);
 }
 
 void RenderWidgetHostViewMac::SetActive(bool active) {
@@ -616,6 +630,14 @@ void RenderWidgetHostViewMac::SetWindowVisibility(bool visible) {
   }
 }
 
+void RenderWidgetHostViewMac::WindowFrameChanged() {
+  if (render_widget_host_) {
+    render_widget_host_->Send(new ViewMsg_WindowFrameChanged(
+        render_widget_host_->routing_id(), GetRootWindowRect(),
+        GetWindowRect()));
+  }
+}
+
 void RenderWidgetHostViewMac::SetBackground(const SkBitmap& background) {
   RenderWidgetHostView::SetBackground(background);
   if (render_widget_host_)
@@ -1518,4 +1540,16 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
   renderWidgetHostView_->im_composing_ = false;
 }
 
+- (void)viewDidMoveToWindow {
+  // If we move into a new window, refresh the frame information. We don't need
+  // to do it if it was the same window as it used to be in, since that case
+  // is covered by DidBecomeSelected.
+  NSWindow* newWindow = [self window];
+  // Pointer comparison only, since we don't know if lastWindow_ is still valid.
+  if (newWindow && (newWindow != lastWindow_)) {
+    lastWindow_ = newWindow;
+    renderWidgetHostView_->WindowFrameChanged();
+  }
+}
+
 @end
diff --git a/chrome/browser/renderer_host/test/test_render_view_host.h b/chrome/browser/renderer_host/test/test_render_view_host.h
index fde21b5..0521de9 100644
--- a/chrome/browser/renderer_host/test/test_render_view_host.h
+++ b/chrome/browser/renderer_host/test/test_render_view_host.h
@@ -78,6 +78,7 @@ class TestRenderWidgetHostView : public RenderWidgetHostView {
   virtual gfx::Rect GetRootWindowRect();
   virtual void SetActive(bool active);
   virtual void SetWindowVisibility(bool visible) {}
+  virtual void WindowFrameChanged() {}
   virtual gfx::PluginWindowHandle AllocateFakePluginWindowHandle();
   virtual void DestroyFakePluginWindowHandle(gfx::PluginWindowHandle window);
   virtual void GPUPluginSetIOSurface(gfx::PluginWindowHandle window,
diff --git a/chrome/common/plugin_messages.h b/chrome/common/plugin_messages.h
index 74de33f..b195f5c 100644
--- a/chrome/common/plugin_messages.h
+++ b/chrome/common/plugin_messages.h
@@ -39,6 +39,11 @@ struct PluginMsg_Init_Params {
   std::vector<std::string> arg_values;
   bool load_manually;
   int host_render_view_routing_id;
+#if defined(OS_MACOSX)
+  gfx::Rect containing_window_frame;
+  gfx::Rect containing_content_frame;
+  bool containing_window_has_focus;
+#endif
 };
 
 struct PluginHostMsg_URLRequest_Params {
@@ -119,6 +124,11 @@ struct ParamTraits<PluginMsg_Init_Params> {
     WriteParam(m, p.arg_values);
     WriteParam(m, p.load_manually);
     WriteParam(m, p.host_render_view_routing_id);
+#if defined(OS_MACOSX)
+    WriteParam(m, p.containing_window_frame);
+    WriteParam(m, p.containing_content_frame);
+    WriteParam(m, p.containing_window_has_focus);
+#endif
   }
   static bool Read(const Message* m, void** iter, param_type* p) {
     return ReadParam(m, iter, &p->containing_window) &&
@@ -127,7 +137,14 @@ struct ParamTraits<PluginMsg_Init_Params> {
            ReadParam(m, iter, &p->arg_names) &&
            ReadParam(m, iter, &p->arg_values) &&
            ReadParam(m, iter, &p->load_manually) &&
-           ReadParam(m, iter, &p->host_render_view_routing_id);
+           ReadParam(m, iter, &p->host_render_view_routing_id)
+#if defined(OS_MACOSX)
+           &&
+           ReadParam(m, iter, &p->containing_window_frame) &&
+           ReadParam(m, iter, &p->containing_content_frame) &&
+           ReadParam(m, iter, &p->containing_window_has_focus)
+#endif
+           ;
   }
   static void Log(const param_type& p, std::wstring* l) {
     l->append(L"(");
@@ -144,6 +161,14 @@ struct ParamTraits<PluginMsg_Init_Params> {
     LogParam(p.load_manually, l);
     l->append(L", ");
     LogParam(p.host_render_view_routing_id, l);
+#if defined(OS_MACOSX)
+    l->append(L", ");
+    LogParam(p.containing_window_frame, l);
+    l->append(L", ");
+    LogParam(p.containing_content_frame, l);
+    l->append(L", ");
+    LogParam(p.containing_window_has_focus, l);
+#endif
     l->append(L")");
   }
 };
diff --git a/chrome/common/plugin_messages_internal.h b/chrome/common/plugin_messages_internal.h
index 05e532b..b5908a8 100644
--- a/chrome/common/plugin_messages_internal.h
+++ b/chrome/common/plugin_messages_internal.h
@@ -233,8 +233,16 @@ IPC_BEGIN_MESSAGES(Plugin)
   IPC_MESSAGE_ROUTED1(PluginMsg_SetWindowFocus,
                       bool /* has_focus */)
 
-  IPC_MESSAGE_ROUTED1(PluginMsg_SetContainerVisibility,
-                      bool /* is_visible */)
+  IPC_MESSAGE_ROUTED0(PluginMsg_ContainerHidden)
+
+  IPC_MESSAGE_ROUTED3(PluginMsg_ContainerShown,
+                      gfx::Rect /* window_frame */,
+                      gfx::Rect /* view_frame */,
+                      bool /* has_focus */)
+
+  IPC_MESSAGE_ROUTED2(PluginMsg_WindowFrameChanged,
+                      gfx::Rect /* window_frame */,
+                      gfx::Rect /* view_frame */)
 #endif
 
   IPC_SYNC_MESSAGE_ROUTED2_0(PluginMsg_WillSendRequest,
diff --git a/chrome/common/render_messages_internal.h b/chrome/common/render_messages_internal.h
index bd23f31..69d7bb2 100644
--- a/chrome/common/render_messages_internal.h
+++ b/chrome/common/render_messages_internal.h
@@ -745,6 +745,11 @@ IPC_BEGIN_MESSAGES(View)
   // Let the RenderView know its window has changed visibility.
   IPC_MESSAGE_ROUTED1(ViewMsg_SetWindowVisibility,
                       bool /* visibile */)
+
+  // Let the RenderView know its window's frame has changed.
+  IPC_MESSAGE_ROUTED2(ViewMsg_WindowFrameChanged,
+                      gfx::Rect /* window frame */,
+                      gfx::Rect /* content view frame */)
 #endif
 
   // Response message to ViewHostMsg_CreateShared/DedicatedWorker.
diff --git a/chrome/plugin/webplugin_delegate_stub.cc b/chrome/plugin/webplugin_delegate_stub.cc
index 80d6e62..a24f7fa 100644
--- a/chrome/plugin/webplugin_delegate_stub.cc
+++ b/chrome/plugin/webplugin_delegate_stub.cc
@@ -123,8 +123,9 @@ void WebPluginDelegateStub::OnMessageReceived(const IPC::Message& msg) {
                         OnSendJavaScriptStream)
 #if defined(OS_MACOSX)
     IPC_MESSAGE_HANDLER(PluginMsg_SetWindowFocus, OnSetWindowFocus)
-    IPC_MESSAGE_HANDLER(PluginMsg_SetContainerVisibility,
-                        OnSetContainerVisibility)
+    IPC_MESSAGE_HANDLER(PluginMsg_ContainerHidden, OnContainerHidden)
+    IPC_MESSAGE_HANDLER(PluginMsg_ContainerShown, OnContainerShown)
+    IPC_MESSAGE_HANDLER(PluginMsg_WindowFrameChanged, OnWindowFrameChanged)
 #endif
     IPC_MESSAGE_HANDLER(PluginMsg_DidReceiveManualResponse,
                         OnDidReceiveManualResponse)
@@ -195,6 +196,9 @@ void WebPluginDelegateStub::OnInit(const PluginMsg_Init_Params& params,
                                     params.load_manually);
 #if defined(OS_MACOSX)
     delegate_->SetFocusNotifier(FocusNotifier);
+    delegate_->WindowFrameChanged(params.containing_window_frame,
+                                  params.containing_content_frame);
+    delegate_->SetWindowHasFocus(params.containing_window_has_focus);
 #endif
   }
 }
@@ -345,8 +349,21 @@ void WebPluginDelegateStub::OnSetWindowFocus(bool has_focus) {
   delegate_->SetWindowHasFocus(has_focus);
 }
 
-void WebPluginDelegateStub::OnSetContainerVisibility(bool is_visible) {
-  delegate_->SetContainerVisibility(is_visible);
+void WebPluginDelegateStub::OnContainerHidden() {
+  delegate_->SetContainerVisibility(false);
+}
+
+void WebPluginDelegateStub::OnContainerShown(gfx::Rect window_frame,
+                                             gfx::Rect view_frame,
+                                             bool has_focus) {
+  delegate_->WindowFrameChanged(window_frame, view_frame);
+  delegate_->SetContainerVisibility(true);
+  delegate_->SetWindowHasFocus(has_focus);
+}
+
+void WebPluginDelegateStub::OnWindowFrameChanged(gfx::Rect window_frame,
+                                                 gfx::Rect view_frame) {
+  delegate_->WindowFrameChanged(window_frame, view_frame);
 }
 #endif  // OS_MACOSX
 
diff --git a/chrome/plugin/webplugin_delegate_stub.h b/chrome/plugin/webplugin_delegate_stub.h
index 5a04758..efe93c10 100644
--- a/chrome/plugin/webplugin_delegate_stub.h
+++ b/chrome/plugin/webplugin_delegate_stub.h
@@ -80,7 +80,10 @@ class WebPluginDelegateStub : public IPC::Channel::Listener,
 
 #if defined(OS_MACOSX)
   void OnSetWindowFocus(bool has_focus);
-  void OnSetContainerVisibility(bool is_visible);
+  void OnContainerHidden();
+  void OnContainerShown(gfx::Rect window_frame, gfx::Rect view_frame,
+                        bool has_focus);
+  void OnWindowFrameChanged(gfx::Rect window_frame, gfx::Rect view_frame);
 #endif
 
   void OnDidReceiveManualResponse(
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index aa433bd..08cb4e0 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -579,6 +579,7 @@ void RenderView::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ViewMsg_SetActive, OnSetActive)
 #if defined(OS_MACOSX)
     IPC_MESSAGE_HANDLER(ViewMsg_SetWindowVisibility, OnSetWindowVisibility)
+    IPC_MESSAGE_HANDLER(ViewMsg_WindowFrameChanged, OnWindowFrameChanged)
 #endif
     IPC_MESSAGE_HANDLER(ViewMsg_SetEditCommandsForNextKeyEvent,
                         OnSetEditCommandsForNextKeyEvent)
@@ -3812,6 +3813,16 @@ void RenderView::OnSetWindowVisibility(bool visible) {
     (*plugin_it)->SetContainerVisibility(visible);
   }
 }
+
+void RenderView::OnWindowFrameChanged(gfx::Rect window_frame,
+                                      gfx::Rect view_frame) {
+  // Inform plugins that their window's frame has changed.
+  std::set<WebPluginDelegateProxy*>::iterator plugin_it;
+  for (plugin_it = plugin_delegates_.begin();
+       plugin_it != plugin_delegates_.end(); ++plugin_it) {
+    (*plugin_it)->WindowFrameChanged(window_frame, view_frame);
+  }
+}
 #endif  // OS_MACOSX
 
 void RenderView::SendExtensionRequest(const std::string& name,
@@ -4335,6 +4346,20 @@ void RenderView::OnWasRestored(bool needs_repainting) {
     (*plugin_it)->SetContainerVisibility(true);
   }
 }
+
+void RenderView::OnSetFocus(bool enable) {
+  RenderWidget::OnSetFocus(enable);
+
+  // RenderWidget's call to setFocus can cause the underlying webview's
+  // activation state to change just like a call to setIsActive.
+  if (enable && webview() && webview()->isActive()) {
+    std::set<WebPluginDelegateProxy*>::iterator plugin_it;
+    for (plugin_it = plugin_delegates_.begin();
+         plugin_it != plugin_delegates_.end(); ++plugin_it) {
+      (*plugin_it)->SetWindowFocus(true);
+    }
+  }
+}
 #endif  // OS_MACOSX
 
 void RenderView::EnsureDocumentTag() {
diff --git a/chrome/renderer/render_view.h b/chrome/renderer/render_view.h
index 7245df1..0066bf3 100644
--- a/chrome/renderer/render_view.h
+++ b/chrome/renderer/render_view.h
@@ -484,6 +484,7 @@ class RenderView : public RenderWidget,
   virtual void DidPaint();
   virtual void DidHandleKeyEvent();
 #if OS_MACOSX
+  virtual void OnSetFocus(bool enable);
   virtual void OnWasHidden();
   virtual void OnWasRestored(bool needs_repainting);
 #endif
@@ -725,6 +726,10 @@ class RenderView : public RenderWidget,
 
 #if defined(OS_MACOSX)
   void OnSetWindowVisibility(bool visible);
+
+  // Notifies the view that window frame has been updated. window_frame and
+  // view_frame are in screen coordinates.
+  void OnWindowFrameChanged(gfx::Rect window_frame, gfx::Rect view_frame);
 #endif
 
   // Execute custom context menu action.
diff --git a/chrome/renderer/render_widget.h b/chrome/renderer/render_widget.h
index 86f2a17..27086a4 100644
--- a/chrome/renderer/render_widget.h
+++ b/chrome/renderer/render_widget.h
@@ -146,7 +146,7 @@ class RenderWidget : public IPC::Channel::Listener,
   void OnRequestMoveAck();
   void OnHandleInputEvent(const IPC::Message& message);
   void OnMouseCaptureLost();
-  void OnSetFocus(bool enable);
+  virtual void OnSetFocus(bool enable);
   void OnImeSetInputMode(bool is_active);
   void OnImeSetComposition(WebKit::WebCompositionCommand command,
                            int cursor_position,
diff --git a/chrome/renderer/webplugin_delegate_proxy.cc b/chrome/renderer/webplugin_delegate_proxy.cc
index 2c87077..f4063e4 100644
--- a/chrome/renderer/webplugin_delegate_proxy.cc
+++ b/chrome/renderer/webplugin_delegate_proxy.cc
@@ -283,6 +283,18 @@ bool WebPluginDelegateProxy::Initialize(const GURL& url,
     params.arg_names.push_back("wmode");
     params.arg_values.push_back("opaque");
   }
+
+  params.containing_window_frame = render_view_->rootWindowRect();
+  // If the renderer isn't currently visible, don't bother asking for anything
+  // else; the plugin will get real data when its renderer becomes visible.
+  if (params.containing_window_frame.IsEmpty()) {
+    params.containing_content_frame = gfx::Rect();
+    params.containing_window_has_focus = false;
+  } else {
+    params.containing_content_frame = render_view_->windowRect();
+    WebKit::WebView* webview = render_view_->webview();
+    params.containing_window_has_focus = webview && webview->isActive();
+  }
 #endif
   params.load_manually = load_manually;
 
@@ -874,16 +886,32 @@ void WebPluginDelegateProxy::SetWindowFocus(bool window_has_focus) {
 }
 
 void WebPluginDelegateProxy::SetContainerVisibility(bool is_visible) {
-  // TODO(stuartmorgan): Split this into two messages, and send location and
-  // focus information with the "became visible" version since the plugins in a
-  // hidden tab will not have been getting live updates.
-  IPC::Message* msg = new PluginMsg_SetContainerVisibility(instance_id_,
-                                                           is_visible);
+  IPC::Message* msg;
+  if (is_visible) {
+    gfx::Rect window_frame = render_view_->rootWindowRect();
+    gfx::Rect view_frame = render_view_->windowRect();
+    WebKit::WebView* webview = render_view_->webview();
+    msg = new PluginMsg_ContainerShown(instance_id_, window_frame, view_frame,
+                                       webview && webview->isActive());
+  } else {
+    msg = new PluginMsg_ContainerHidden(instance_id_);
+  }
   // Make sure visibility events are delivered in the right order relative to
   // sync messages they might interact with (Paint, HandleEvent, etc.).
   msg->set_unblock(true);
   Send(msg);
 }
+
+void WebPluginDelegateProxy::WindowFrameChanged(gfx::Rect window_frame,
+                                                gfx::Rect view_frame) {
+  IPC::Message* msg = new PluginMsg_WindowFrameChanged(instance_id_,
+                                                       window_frame,
+                                                       view_frame);
+  // Make sure frame events are delivered in the right order relative to
+  // sync messages they might interact with (e.g., HandleEvent).
+  msg->set_unblock(true);
+  Send(msg);
+}
 #endif  // OS_MACOSX
 
 void WebPluginDelegateProxy::OnSetWindow(gfx::PluginWindowHandle window) {
diff --git a/chrome/renderer/webplugin_delegate_proxy.h b/chrome/renderer/webplugin_delegate_proxy.h
index 1afbacd9..98eb1ee 100644
--- a/chrome/renderer/webplugin_delegate_proxy.h
+++ b/chrome/renderer/webplugin_delegate_proxy.h
@@ -75,6 +75,8 @@ class WebPluginDelegateProxy
   virtual void SetWindowFocus(bool window_has_focus);
   // Inform the plugin that its container (window/tab) has changed visibility.
   virtual void SetContainerVisibility(bool is_visible);
+  // Inform the plugin that its enclosing window's frame has changed.
+  virtual void WindowFrameChanged(gfx::Rect window_frame, gfx::Rect view_frame);
 #endif
 
   // IPC::Channel::Listener implementation: