Fix VK animation related issues

chrome/browser/ui/ash/ash_keyboard_controller_proxy.cc

Index: chrome/browser/ui/ash/ash_keyboard_controller_proxy.cc
diff --git a/chrome/browser/ui/ash/ash_keyboard_controller_proxy.cc b/chrome/browser/ui/ash/ash_keyboard_controller_proxy.cc
index 6e40b63f8ee6bb81242d9dcc194babca4c8ca7e2..8aed9c330a282baacc7077643d3db33e961eb02a 100644
--- a/chrome/browser/ui/ash/ash_keyboard_controller_proxy.cc
+++ b/chrome/browser/ui/ash/ash_keyboard_controller_proxy.cc
@@ -41,6 +41,10 @@ const char* kVirtualKeyboardExtensionID = "mppnpdlheglhdfmldimlhpnegondlapf";
 // The virtual keyboard show/hide animation duration.
 const int kAnimationDurationMs = 200;
 
+// The opacity of virtual keyboard container when show animation starts or
+// hide animation finishes.
+const float kAnimationStartOrAfterHideOpacity = 0.2f;
+
 Context::Type TextInputTypeToGeneratedInputTypeEnum(ui::TextInputType type) {
   switch (type) {
     case ui::TEXT_INPUT_TYPE_NONE:
@@ -158,17 +162,18 @@ void AshKeyboardControllerProxy::ShowKeyboardContainer(
     gfx::Transform transform;
     transform.Translate(0, GetKeyboardWindow()->bounds().height());
     container->SetTransform(transform);
-    container->layer()->SetOpacity(0.0);
+    container->layer()->SetOpacity(kAnimationStartOrAfterHideOpacity);
   }
 
+  container_animator->set_preemption_strategy(
+      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+
   {
     // Scope the following animation settings as we don't want to animate
     // visibility change that triggered by a call to the base class function
     // ShowKeyboardContainer with these settings. The container should become
     // visible immediately.
     ui::ScopedLayerAnimationSettings settings(container_animator);
-    settings.SetPreemptionStrategy(
-      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
     settings.SetTweenType(gfx::Tween::EASE_IN);
     settings.SetTransitionDuration(
         base::TimeDelta::FromMilliseconds(kAnimationDurationMs));
@@ -197,15 +202,13 @@ void AshKeyboardControllerProxy::HideKeyboardContainer(
   container_animator->AddObserver(this);
   animation_window_ = container;
   ui::ScopedLayerAnimationSettings settings(container_animator);
-  settings.SetPreemptionStrategy(
-      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
   settings.SetTweenType(gfx::Tween::EASE_OUT);
   settings.SetTransitionDuration(
       base::TimeDelta::FromMilliseconds(kAnimationDurationMs));
   gfx::Transform transform;
   transform.Translate(0, GetKeyboardWindow()->bounds().height());
   container->SetTransform(transform);
-  container->layer()->SetOpacity(0.0);
+  container->layer()->SetOpacity(kAnimationStartOrAfterHideOpacity);
 }
 
 void AshKeyboardControllerProxy::OnLayerAnimationEnded(
@@ -213,7 +216,7 @@ void AshKeyboardControllerProxy::OnLayerAnimationEnded(
   if (!animation_window_)
     return;
   ui::LayerAnimator* animator = animation_window_->layer()->GetAnimator();
-  if (animator && !animator->is_animating()) {
+  if (!animator->is_animating()) {
     KeyboardControllerProxy::HideKeyboardContainer(animation_window_);
     animator->RemoveObserver(this);

[James Cook, 2014/01/16 17:55:03]

Is it possible to leak this observer?  I'm not clear on what happens if
OnLayerAnimationEnded() is called but this if() branch isn't taken.

[bshe, 2014/01/16 20:09:04]

We have a few animations at the same time. So OnLayerAnimationEnded may called
multiple times. And we only want to remove the observer if the last animation
finished, hence the if() branch. If the remaining animation is somehow aborted,
the observer should be removed in the OnLayerAnimationAborted below. So it
should be safe.

On 2014/01/16 17:55:03, James Cook wrote:

     animation_window_ = NULL;
@@ -224,10 +227,7 @@ void AshKeyboardControllerProxy::OnLayerAnimationAborted(
     ui::LayerAnimationSequence* sequence) {
   if (!animation_window_)
     return;
-  ui::LayerAnimator* animator = animation_window_->layer()->GetAnimator();
-  if (animator) {
-    animator->RemoveObserver(this);
-  }
+  animation_window_->layer()->GetAnimator()->RemoveObserver(this);
   animation_window_ = NULL;
 };