Use PrintWindow() to implement snapshots on windows 8.1+

content/browser/renderer_host/render_widget_host_impl.cc

 // 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_impl.h"
 
 #include <math.h>
 
 #include <set>
 #include <tuple>
@@ skipping 1750 matching lines @@
 }
 
 void RenderWidgetHostImpl::OnGpuSwapBuffersCompletedInternal(
     const ui::LatencyInfo& latency_info) {
   ui::LatencyInfo::LatencyComponent window_snapshot_component;
   if (latency_info.FindLatency(ui::BROWSER_SNAPSHOT_FRAME_NUMBER_COMPONENT,
                                GetLatencyComponentId(),
                                &window_snapshot_component)) {
     int sequence_number =
         static_cast<int>(window_snapshot_component.sequence_number);
-#if defined(OS_MACOSX)
-    // On Mac, when using CoreAnimation, there is a delay between when content
-    // is drawn to the screen, and when the snapshot will actually pick up
-    // that content. Insert a manual delay of 1/6th of a second (to simulate
-    // 10 frames at 60 fps) before actually taking the snapshot.
+#if defined(OS_MACOSX) || defined(OS_WIN)
+    // On Mac, when using CoreAnimation, or Win32 when using GDI, there is a
+    // delay between when content is drawn to the screen, and when the
+    // snapshot will actually pick up that content. Insert a manual delay of
+    // 1/6th of a second (to simulate 10 frames at 60 fps) before actually
+    // taking the snapshot.
     base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
         FROM_HERE,
         base::Bind(&RenderWidgetHostImpl::WindowSnapshotReachedScreen,
                    weak_factory_.GetWeakPtr(), sequence_number),
         base::TimeDelta::FromSecondsD(1. / 6));
 #else
     WindowSnapshotReachedScreen(sequence_number);
 #endif
   }
 
@@ skipping 870 matching lines @@
 
   // After navigation, if a frame belonging to the new page is received, stop
   // the timer that triggers clearing the graphics of the last page.
   if (last_received_content_source_id_ >= current_content_source_id_ &&
       new_content_rendering_timeout_->IsRunning()) {
     new_content_rendering_timeout_->Stop();
   }
 }
 
 }  // namespace content