Ignores synthetic mouse events in ImmersiveModeControllerAsh::OnMouseEvent()....

Ignores synthetic mouse events in ImmersiveModeControllerAsh::OnMouseEvent(). Counterintuitively, we get synthetic mouse events when aura::client::CursorClient::IsMouseEventsEnabled() == false.

BUG=252230
Test=Manual, see bug

Review URL: https://chromiumcodereview.appspot.com/17514009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@208097 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/frame/immersive_mode_controller_ash.cc

@@ -461,6 +461,11 @@ void ImmersiveModeControllerAsh::OnMouseEvent(ui::MouseEvent* event) {
   if (!enabled_)
     return;
 
+  // Counterintuitively, we can still get synthesized mouse moves when
+  // aura::client::CursorClient::IsMouseEventsEnabled() == false.
+  if (event->flags() & ui::EF_IS_SYNTHESIZED)
+    return;
+
   if (event->type() != ui::ET_MOUSE_MOVED &&
       event->type() != ui::ET_MOUSE_PRESSED &&
       event->type() != ui::ET_MOUSE_RELEASED &&