Store physical backing size in ViewAndroid

ui/android/view_android.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/android/view_android.h"
 
 #include <algorithm>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 105 matching lines @@
   DCHECK(std::find(children_.begin(), children_.end(), child) ==
          children_.end());
   DCHECK(!SubtreeHasEventForwarder(child) || !ViewTreeHasEventForwarder(this))
       << "Only one event handler is allowed.";
 
   // The new child goes to the top, which is the end of the list.
   children_.push_back(child);
   if (child->parent_)
     child->RemoveFromParent();
   child->parent_ = this;
+  child->OnPhysicalBackingSizeChanged(physical_size_);
 }
 
 // static
 bool ViewAndroid::ViewTreeHasEventForwarder(ViewAndroid* view) {
   ViewAndroid* v = view;
   do {
     if (v->has_event_forwarder())
       return true;
     v = v->parent_;
   } while (v);
@@ skipping 84 matching lines @@
 
   return parent_ ? parent_->GetViewAndroidDelegate() : delegate;
 }
 
 cc::Layer* ViewAndroid::GetLayer() const {
   return layer_.get();
 }
 
 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) {
   layout_params_ = params;
 }
 
 bool ViewAndroid::StartDragAndDrop(const JavaRef<jstring>& jtext,
                                    const JavaRef<jobject>& jimage) {
   ScopedJavaLocalRef<jobject> delegate(GetViewAndroidDelegate());
   if (delegate.is_null())
@@ skipping 32 matching lines @@
 }
 
 int ViewAndroid::GetSystemWindowInsetBottom() {
   ScopedJavaLocalRef<jobject> delegate(GetViewAndroidDelegate());
   if (delegate.is_null())
     return 0;
   JNIEnv* env = base::android::AttachCurrentThread();
   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(
       base::Bind(&ViewAndroid::SendTouchEventToClient, for_touch_handle),
       event);
 }
 
 bool ViewAndroid::SendTouchEventToClient(bool for_touch_handle,
                                          ViewClient* client,
                                          const MotionEventAndroid& event) {
@@ skipping 40 matching lines @@
         matched = bound.Contains(e->GetX(0), e->GetY(0));
       }
       if (matched && child->HitTest(send_to_client, *e))
         return true;
     }
   }
   return false;
 }
 
 }  // namespace ui