Store physical backing size in ViewAndroid

ui/android/view_android.cc

Index: ui/android/view_android.cc
diff --git a/ui/android/view_android.cc b/ui/android/view_android.cc
index 15e51a0042ca48b6eb5c29d0bbbc6cafdb9541a3..fbaf2e74d6316ffe5f6328833952fc93adcd3835 100644
--- a/ui/android/view_android.cc
+++ b/ui/android/view_android.cc
@@ -123,6 +123,7 @@ void ViewAndroid::AddChild(ViewAndroid* child) {
   if (child->parent_)
     child->RemoveFromParent();
   child->parent_ = this;
+  child->OnPhysicalBackingSizeChanged(physical_size_);
 }
 
 // static
@@ -229,6 +230,11 @@ void ViewAndroid::SetLayer(scoped_refptr<cc::Layer> layer) {
   layer_ = layer;
 }
 
+void ViewAndroid::UpdateLayerBounds() {
+  if (layer_)
+    layer_->SetBounds(physical_size_);
+}
+
 void ViewAndroid::SetLayout(ViewAndroid::LayoutParams params) {
   layout_params_ = params;
 }
@@ -279,6 +285,22 @@ int ViewAndroid::GetSystemWindowInsetBottom() {
   return Java_ViewAndroidDelegate_getSystemWindowInsetBottom(env, delegate);
 }
 
+void ViewAndroid::OnPhysicalBackingSizeChanged(const gfx::Size& size) {
+  if (physical_size_ == size)
+    return;
+  physical_size_ = size;
+  UpdateLayerBounds();
+  if (client_ && client_->OnPhysicalBackingSizeChanged())

[boliu, 2017/04/29 00:18:40]

this makes no sense, why would client ever want to cancel this?

looking at the use cases, looks like returning false in cases where
OnPhysicalBackingSizeChanged currently returns true works just fine?

[Jinsuk Kim, 2017/04/30 00:23:50]

Can do without bool return type. Changed to void.

+    return;
+
+  for (auto* child : children_)
+    child->OnPhysicalBackingSizeChanged(size);
+}
+
+gfx::Size ViewAndroid::GetPhysicalBackingSize() {
+  return physical_size_;
+}
+
 bool ViewAndroid::OnTouchEvent(const MotionEventAndroid& event,
                                bool for_touch_handle) {
   return HitTest(