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..9b5a2bf3de3ea8ec754af1210c85da9d4e16ddf6 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
@@ -227,6 +228,12 @@ cc::Layer* ViewAndroid::GetLayer() const {
 
 void ViewAndroid::SetLayer(scoped_refptr<cc::Layer> layer) {
   layer_ = layer;
+  UpdateLayerBounds();
+}
+
+void ViewAndroid::UpdateLayerBounds() {

[Khushal, 2017/05/04 00:01:22]

I think the caller should update the size *if* they want it to match the
physical backing size. None of the views in content need this. CVC needed it
earlier because its layer used to be a drawing solid color layer, to handle the
case where there was no frame from the renderer. Now that is done using LTH bg
color.

[Jinsuk Kim, 2017/05/08 07:40:44]

Sorry I don't get the suggestion made here. Would you elaborate? How do we know
when callers want the two sizes (view & physical backing) to be matched? 

[Khushal, 2017/05/08 17:55:37]

Sorry, my point was that VA shouldn't need to do this. The caller can do
view_.GetLayer()->SetBounds(view_.GetPhysicalBackingSize()), if they want their
size to match the physical backing size. VAs are going to be used in the UI and
other cases will not necessarily want these 2 sizes to always match.

And I think it should be fine if you don't do this at all for views in content.
The layers there are plain old hierarchy cc::Layers, not necessary to set their
bounds.

[Jinsuk Kim, 2017/05/10 06:05:27]

Removed |UpdateLayerBounds()|

+  if (layer_)
+    layer_->SetBounds(physical_size_);
 }
 
 void ViewAndroid::SetLayout(ViewAndroid::LayoutParams params) {
@@ -279,6 +286,20 @@ int ViewAndroid::GetSystemWindowInsetBottom() {
   return Java_ViewAndroidDelegate_getSystemWindowInsetBottom(env, delegate);
 }
 
+void ViewAndroid::OnPhysicalBackingSizeChanged(const gfx::Size& size) {

[Khushal, 2017/05/04 00:01:22]

Something still needs to poke RWHVA to send the updated size to the renderer.
Earlier CVC::onPhysicalBackingSizeChanged was doing it. Is that somewhere else
in this patch?

[Jinsuk Kim, 2017/05/08 07:40:44]

It was present in the earlier patches but removed here, and that was the reason
some tests failed. Put it back. 

+  if (physical_size_ == size)
+    return;
+  physical_size_ = size;
+  UpdateLayerBounds();
+
+  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(