Add ink drop masking to TrayBackgroundView

ui/views/animation/ink_drop_impl.cc

 // Copyright 2015 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/ink_drop_impl.h"
 
 #include "base/auto_reset.h"
 #include "base/timer/timer.h"
 #include "ui/compositor/layer.h"
 #include "ui/views/animation/ink_drop_highlight.h"
@@ skipping 557 matching lines @@
           this, animation_duration, explode);
     case InkDropImpl::AutoHighlightMode::SHOW_ON_RIPPLE:
       return base::MakeUnique<ShowHighlightOnRippleVisibleState>(
           this, animation_duration, explode);
   }
   // Required for some compilers.
   NOTREACHED();
   return nullptr;
 }
 
-InkDropImpl::InkDropImpl(InkDropHost* ink_drop_host)
+InkDropImpl::InkDropImpl(InkDropHost* ink_drop_host,
+                         const gfx::Size& layer_size)
     : ink_drop_host_(ink_drop_host),
       root_layer_(new ui::Layer(ui::LAYER_NOT_DRAWN)),
       root_layer_added_to_host_(false),
       show_highlight_on_hover_(true),
       show_highlight_on_focus_(false),
       is_hovered_(false),
       is_focused_(false),
       exiting_highlight_state_(false),
       destroying_(false) {
+  root_layer_->SetBounds(gfx::Rect(layer_size));
   SetAutoHighlightMode(AutoHighlightMode::NONE);
   root_layer_->set_name("InkDropImpl:RootLayer");
 }
 
 InkDropImpl::~InkDropImpl() {
   destroying_ = true;
   // Setting a no-op state prevents animations from being triggered on a null
   // |ink_drop_ripple_| as a side effect of the tear down.
   SetHighlightState(base::MakeUnique<DestroyingHighlightState>());
 
@@ skipping 15 matching lines @@
 
 void InkDropImpl::SetAutoHighlightMode(AutoHighlightMode auto_highlight_mode) {
   // Exit the current state completely first in case state tear down accesses
   // the current |highlight_state_factory_| instance.
   ExitHighlightState();
   highlight_state_factory_ =
       base::MakeUnique<HighlightStateFactory>(auto_highlight_mode, this);
   SetHighlightState(highlight_state_factory_->CreateStartState());
 }
 
+void InkDropImpl::UpdateLayerSize(const gfx::Size& layer_size) {
+  root_layer_->SetBounds(gfx::Rect(layer_size));

[bruthig, 2016/11/14 19:09:38]

nit: A comment here saying that "we are updating |root_layer_|'s size because it
affects the clipping when a mask is applied" would be super helpful. It might be
worth mentioning that it only affects clipping when the masking layer is not
null.

[mohsen, 2016/11/14 20:19:39]

Done.

+}
+
 InkDropState InkDropImpl::GetTargetInkDropState() const {
   if (!ink_drop_ripple_)
     return InkDropState::HIDDEN;
   return ink_drop_ripple_->target_ink_drop_state();
 }
 
 void InkDropImpl::AnimateToState(InkDropState ink_drop_state) {
   // Never animate hidden -> hidden, since that will add layers which may never
   // be needed. Other same-state transitions may restart animations.
   if (ink_drop_state == InkDropState::HIDDEN &&
@@ skipping 170 matching lines @@
                                        "within a call to "
                                        "HighlightState::Exit().";
   if (highlight_state_) {
     base::AutoReset<bool> exit_guard(&exiting_highlight_state_, true);
     highlight_state_->Exit();
   }
   highlight_state_ = nullptr;
 }
 
 }  // namespace views