Hack in order to fix crbug.com/394672 in M38

This CL effectively reverts https://codereview.chromium.org/344793013 for
Windows only.

BUG=394672
TEST=Manual, see bug

Review URL: https://codereview.chromium.org/446673004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288007 0039d316-1c4b-4281-b951-d872f2087c98

ui/aura/window_event_dispatcher.cc

@@ -388,6 +388,9 @@ void WindowEventDispatcher::UpdateCapture(Window* old_capture,
 }
 
 void WindowEventDispatcher::OnOtherRootGotCapture() {
+  // Sending the mouse exit causes bugs on Windows (e.g. crbug.com/394672).
+  // TODO(pkotwicz): Fix the bugs and send mouse exit on Windows too.
+#if !defined(OS_WIN)
   if (mouse_moved_handler_) {
     // Dispatch a mouse exit to reset any state associated with hover. This is
     // important when going from no window having capture to a window having
@@ -397,6 +400,7 @@ void WindowEventDispatcher::OnOtherRootGotCapture() {
     if (details.dispatcher_destroyed)
       return;
   }
+#endif
 
   mouse_moved_handler_ = NULL;
   mouse_pressed_handler_ = NULL;

ui/views/widget/widget_interactive_uitest.cc

@@ -947,10 +947,10 @@ TEST_F(WidgetCaptureTest, FailedCaptureRequestIsNoop) {
   EXPECT_TRUE(mouse_view2->pressed());
 }
 
-#if !defined(OS_CHROMEOS)
+#if !defined(OS_CHROMEOS) && !defined(OS_WIN)
 // Test that a synthetic mouse exit is sent to the widget which was handling
 // mouse events when a different widget grabs capture.
-// TODO(pkotwicz): Make test pass on CrOS.
+// TODO(pkotwicz): Make test pass on CrOS and Windows.
 TEST_F(WidgetCaptureTest, MouseExitOnCaptureGrab) {
   Widget widget1;
   Widget::InitParams params1 =