exo: Replace fling cancel with generic zero distance scroll

components/exo/pointer.cc

Index: components/exo/pointer.cc
diff --git a/components/exo/pointer.cc b/components/exo/pointer.cc
index 46fbcb109b8397317b0599b9f6c6e5d28149da82..e83dbcd48d315fc25046eda23e521cde46d2e492 100644
--- a/components/exo/pointer.cc
+++ b/components/exo/pointer.cc
@@ -247,8 +247,11 @@ void Pointer::OnMouseEvent(ui::MouseEvent* event) {
       }
       break;
     case ui::ET_SCROLL_FLING_CANCEL:
-      if (focus_) {
-        delegate_->OnPointerScrollCancel(event->time_stamp());
+      if (focus_ && last_event_type_ == ui::ET_SCROLL_FLING_START) {
+        delegate_->OnPointerScroll(event->time_stamp(), gfx::Vector2dF(),
+                                   false);
+        delegate_->OnPointerFrame();
+        delegate_->OnPointerScrollStop(event->time_stamp());
         delegate_->OnPointerFrame();
       }
       break;
@@ -263,8 +266,10 @@ void Pointer::OnMouseEvent(ui::MouseEvent* event) {
       break;
   }
 
-  if ((event->flags() & ui::EF_IS_SYNTHESIZED) == 0)
-    is_direct_input_ = (event->flags() & ui::EF_DIRECT_INPUT) != 0;
+  if (!(event->flags() & ui::EF_IS_SYNTHESIZED)) {
+    is_direct_input_ = event->flags() & ui::EF_DIRECT_INPUT;
+    last_event_type_ = event->type();
+  }
 
   // Update cursor widget to reflect current focus and pointer location.
   if (focus_ && !is_direct_input_) {