Mark the ET_MOUSE_MOVED created from a pointer grab as synthesized.

ui/aura/window_event_dispatcher.cc

Index: ui/aura/window_event_dispatcher.cc
diff --git a/ui/aura/window_event_dispatcher.cc b/ui/aura/window_event_dispatcher.cc
index dc286d0826545413afb7ddb91314056bf84d439d..7f0d85105b6adf9a7174ea4a1ee2d489807c1edb 100644
--- a/ui/aura/window_event_dispatcher.cc
+++ b/ui/aura/window_event_dispatcher.cc
@@ -226,6 +226,8 @@ gfx::Point WindowEventDispatcher::GetLastMouseLocationInRoot() const {
 
 void WindowEventDispatcher::OnHostLostMouseGrab() {
   mouse_pressed_handler_ = NULL;
+  LOG(ERROR) << "mouse_moved_handler_ = NULL (was " << mouse_moved_handler_
+             << ")";
   mouse_moved_handler_ = NULL;
 }
 
@@ -327,8 +329,11 @@ void WindowEventDispatcher::OnWindowHidden(Window* invisible,
   // longer receive mouse events.
   if (invisible->Contains(mouse_pressed_handler_))
     mouse_pressed_handler_ = NULL;
-  if (invisible->Contains(mouse_moved_handler_))
+  if (invisible->Contains(mouse_moved_handler_)) {
+    LOG(ERROR) << "mouse_moved_handler_ = NULL (was " << mouse_moved_handler_
+               << ")";
     mouse_moved_handler_ = NULL;
+  }
 
   // If events are being dispatched from a nested message-loop, and the target
   // of the outer loop is hidden or moved to another dispatcher during
@@ -376,8 +381,11 @@ void WindowEventDispatcher::UpdateCapture(Window* old_capture,
   // |mouse_moved_handler_| may have been set to a Window in a different root
   // (see below). Clear it here to ensure we don't end up referencing a stale
   // Window.
-  if (mouse_moved_handler_ && !window()->Contains(mouse_moved_handler_))
+  if (mouse_moved_handler_ && !window()->Contains(mouse_moved_handler_)) {
+    LOG(ERROR) << "mouse_moved_handler_ = NULL (was " << mouse_moved_handler_
+               << ")";
     mouse_moved_handler_ = NULL;
+  }
 
   if (old_capture && old_capture->GetRootWindow() == window() &&
       old_capture->delegate()) {
@@ -396,8 +404,11 @@ void WindowEventDispatcher::UpdateCapture(Window* old_capture,
   if (new_capture) {
     // Make all subsequent mouse events go to the capture window. We shouldn't
     // need to send an event here as OnCaptureLost() should take care of that.
-    if (mouse_moved_handler_ || Env::GetInstance()->IsMouseButtonDown())
+    if (mouse_moved_handler_ || Env::GetInstance()->IsMouseButtonDown()) {
+      LOG(ERROR) << "mouse_moved_handler_ = " << new_capture << " (was "
+                 << mouse_moved_handler_ << ")";
       mouse_moved_handler_ = new_capture;
+    }
   } else {
     // Make sure mouse_moved_handler gets updated.
     DispatchDetails details = SynthesizeMouseMoveEvent();
@@ -426,6 +437,8 @@ void WindowEventDispatcher::OnOtherRootGotCapture() {
   }
 #endif
 
+  LOG(ERROR) << "mouse_moved_handler_ = NULL (was " << mouse_moved_handler_
+             << ")";
   mouse_moved_handler_ = NULL;
   mouse_pressed_handler_ = NULL;
 }
@@ -810,10 +823,13 @@ DispatchDetails WindowEventDispatcher::PreDispatchMouseEvent(
   // We allow synthesized mouse exit events through even if mouse events are
   // disabled. This ensures that hover state, etc on controls like buttons is
   // cleared.
+  if (cursor_client)
+    LOG(ERROR) << cursor_client->IsMouseEventsEnabled();
   if (cursor_client &&
       !cursor_client->IsMouseEventsEnabled() &&
       (event->flags() & ui::EF_IS_SYNTHESIZED) &&
       (event->type() != ui::ET_MOUSE_EXITED)) {
+    LOG(ERROR) << "drop";
     event->SetHandled();
     return DispatchDetails();
   }
@@ -824,6 +840,7 @@ DispatchDetails WindowEventDispatcher::PreDispatchMouseEvent(
   if (IsEventCandidateForHold(*event) && !dispatching_held_event_) {
     if (move_hold_count_) {
       held_move_event_.reset(new ui::MouseEvent(*event, target, window()));
+      LOG(ERROR) << "drop";
       event->SetHandled();
       return DispatchDetails();
     } else {
@@ -843,6 +860,8 @@ DispatchDetails WindowEventDispatcher::PreDispatchMouseEvent(
           event->SetHandled();
           return details;
         }
+        LOG(ERROR) << "mouse_moved_handler_ = NULL (was "
+                   << mouse_moved_handler_ << ")";
         mouse_moved_handler_ = NULL;
       }
       break;
@@ -862,22 +881,28 @@ DispatchDetails WindowEventDispatcher::PreDispatchMouseEvent(
         DispatchDetails target_details = details;
         target_details.target_destroyed = !live_window.Contains(target);
         if (details.dispatcher_destroyed) {
+          LOG(ERROR) << "drop";
           event->SetHandled();
           return target_details;
         }
         // If the |mouse_moved_handler_| changes out from under us, assume a
         // nested run loop ran and we don't need to do anything.
         if (mouse_moved_handler_ != old_mouse_moved_handler) {
+          LOG(ERROR) << "drop";
           event->SetHandled();
           return target_details;
         }
         if (details.target_destroyed || target_details.target_destroyed) {
+          LOG(ERROR) << "mouse_moved_handler_ = NULL (was "
+                     << mouse_moved_handler_ << ")";
           mouse_moved_handler_ = NULL;
           event->SetHandled();
           return target_details;
         }
         live_window.Remove(target);
 
+        LOG(ERROR) << "mouse_moved_handler_ = " << target << " (was "
+                   << mouse_moved_handler_ << ")";
         mouse_moved_handler_ = target;
         details =
             DispatchMouseEnterOrExit(target, *event, ui::ET_MOUSE_ENTERED);