Clear page display after navigation if no rendered output arrives

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 <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 1546 matching lines @@
         frame->metadata.device_scale_factor,
         frame->metadata.latency_info,
         &frame->metadata.satisfies_sequences);
   } else {
     DLOG(ERROR) << "Received unexpected frame type.";
     bad_message::ReceivedBadMessage(render_widget_host_->GetProcess(),
                                     bad_message::RWHVM_UNEXPECTED_FRAME_TYPE);
   }
 }
 
+void RenderWidgetHostViewMac::ClearCompositorFrame() {
+  if (delegated_frame_host_)
+    delegated_frame_host_->ClearDelegatedFrame();
+}
+
 void RenderWidgetHostViewMac::GetScreenInfo(blink::WebScreenInfo* results) {
   *results = GetWebScreenInfo(GetNativeView());
 }
 
 bool RenderWidgetHostViewMac::GetScreenColorProfile(
     std::vector<char>* color_profile) {
   DCHECK(color_profile->empty());
   NSWindow* window = GetWebContents()->GetTopLevelNativeWindow();
   return gfx::GetDisplayColorProfile(window, color_profile);
 }
@@ skipping 1828 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