Add ink drop masking to TrayBackgroundView

ui/views/animation/test/test_ink_drop.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/animation/test/test_ink_drop.h"
 
 namespace views {
 namespace test {
 
 TestInkDrop::TestInkDrop() : state_(InkDropState::HIDDEN), is_hovered_(false) {}
 TestInkDrop::~TestInkDrop() {}
 
+void TestInkDrop::HostSizeChanged(const gfx::Size& new_size) {}
+
 InkDropState TestInkDrop::GetTargetInkDropState() const {
   return state_;
 }
 
 void TestInkDrop::AnimateToState(InkDropState ink_drop_state) {
   state_ = ink_drop_state;
 }
 
 void TestInkDrop::SnapToActivated() {
   state_ = InkDropState::ACTIVATED;
 }
 
 void TestInkDrop::SetHovered(bool is_hovered) {
   is_hovered_ = is_hovered;
 }
 
 void TestInkDrop::SetFocused(bool is_focused) {}
 
 }  // namespace test
 }  // namespace views