Change the order of handling inkdrop and mouse event

 InkDrop is handled before View::OnMouseEvent() in OnMouseEvent().
So, If I want to override the functions associated with InkDrop(ex : CreateInkDropHighlight()),
there is a problem with not getting the something appropriate(ex. Button::STATE).

 But, changing the order of handling inkdrop and mouse event causes crashes on windows.
(See, http:://www.crbug.org/902279.)
The cause of this crashes is calling views::OnMouseEvent() might delete "this".
So We Check if it's being detroyed to avoid crashes.


Bug: none
Change-Id: I2051ddbff9d674418c42e8fd81fcd9a4ab47a984
Reviewed-on: https://chromium-review.googlesource.com/c/1335068Reviewed-by: Mohsen Izadi <mohsen@chromium.org>
Commit-Queue: Mohsen Izadi <mohsen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611513}

ui/views/animation/ink_drop_host_view.cc

@@ -230,6 +230,12 @@ void InkDropHostView::OnBlur() {
 }
 
 void InkDropHostView::OnMouseEvent(ui::MouseEvent* event) {
+  auto weak_ptr = weak_factory_.GetWeakPtr();
+  View::OnMouseEvent(event);
+  if (!weak_ptr) {
+    // Calling View::OnMouseEvent() might destroy |this|.
+    return;
+  }
   switch (event->type()) {
     case ui::ET_MOUSE_ENTERED:
       GetInkDrop()->SetHovered(true);
@@ -243,7 +249,6 @@ void InkDropHostView::OnMouseEvent(ui::MouseEvent* event) {
     default:
       break;
   }
-  View::OnMouseEvent(event);
 }
 
 std::unique_ptr<InkDropImpl> InkDropHostView::CreateDefaultInkDropImpl() {

ui/views/animation/ink_drop_host_view.h

@@ -205,6 +205,8 @@ class VIEWS_EXPORT InkDropHostView : public View {
 
   std::unique_ptr<views::InkDropMask> ink_drop_mask_;
 
+  base::WeakPtrFactory<InkDropHostView> weak_factory_{this};
+
   DISALLOW_COPY_AND_ASSIGN(InkDropHostView);
 };