Close the screenshot flash effect before the screenshot task is actually executed.

The screenshot task takes time so the flash could be noticeably long.

BUG=120092
TEST=manually

Review URL: https://chromiumcodereview.appspot.com/9854012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@128925 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/ash/screenshot_taker.cc

@@ -117,7 +117,9 @@ void ScreenshotTaker::HandleTakeScreenshot(aura::Window* window) {
 
 void ScreenshotTaker::CloseVisualFeedbackLayer(const base::Closure& task) {
   visual_feedback_layer_.reset();
-  task.Run();
+  // Hide the visual feedback immediately because |task| may take a long time
+  // to finish.
+  MessageLoopForUI::current()->PostTask(FROM_HERE, task);
 }
 
 void ScreenshotTaker::DisplayVisualFeedback(const gfx::Rect& rect,