Account for failure of coordinate space transformations in browser

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 1541 matching lines @@
     const ui::LatencyInfo& latency) {
   render_widget_host_->ForwardTouchEventWithLatencyInfo(event, latency);
 }
 
 void RenderWidgetHostViewMac::ProcessGestureEvent(
     const blink::WebGestureEvent& event,
     const ui::LatencyInfo& latency) {
   render_widget_host_->ForwardGestureEventWithLatencyInfo(event, latency);
 }
 
-gfx::Point RenderWidgetHostViewMac::TransformPointToLocalCoordSpace(
+bool RenderWidgetHostViewMac::TransformPointToLocalCoordSpace(
     const gfx::Point& point,
-    const cc::SurfaceId& original_surface) {
-  gfx::Point transformed_point;
+    const cc::SurfaceId& original_surface,
+    gfx::Point* transformed_point) {
   // Transformations use physical pixels rather than DIP, so conversion
   // is necessary.
   float scale_factor = display::Screen::GetScreen()
                            ->GetDisplayNearestWindow(cocoa_view_)
                            .device_scale_factor();
   gfx::Point point_in_pixels = gfx::ConvertPointToPixel(scale_factor, point);
-  transformed_point =
-      browser_compositor_->GetDelegatedFrameHost()
-          ->TransformPointToLocalCoordSpace(point_in_pixels, original_surface);
-  return gfx::ConvertPointToDIP(scale_factor, transformed_point);
+  if (!browser_compositor_->GetDelegatedFrameHost()
+           ->TransformPointToLocalCoordSpace(point_in_pixels, original_surface,
+                                             transformed_point))
+    return false;
+  *transformed_point = gfx::ConvertPointToDIP(scale_factor, *transformed_point);
+  return true;
 }
 
-gfx::Point RenderWidgetHostViewMac::TransformPointToCoordSpaceForView(
+bool RenderWidgetHostViewMac::TransformPointToCoordSpaceForView(
     const gfx::Point& point,
-    RenderWidgetHostViewBase* target_view) {
+    RenderWidgetHostViewBase* target_view,
+    gfx::Point* transformed_point) {
   return browser_compositor_->GetDelegatedFrameHost()
-      ->TransformPointToCoordSpaceForView(point, target_view);
+      ->TransformPointToCoordSpaceForView(point, target_view,
+                                          transformed_point);
 }
 
 bool RenderWidgetHostViewMac::Send(IPC::Message* message) {
   if (render_widget_host_)
     return render_widget_host_->Send(message);
   delete message;
   return false;
 }
 
 void RenderWidgetHostViewMac::ShutdownHost() {
@@ skipping 1799 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end