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..f7bfb0f32df54d0b0e6bf7f4f3e6c6af9bb31be4 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
@@ -279,6 +280,20 @@ int ViewAndroid::GetSystemWindowInsetBottom() {
   return Java_ViewAndroidDelegate_getSystemWindowInsetBottom(env, delegate);
 }
 
+void ViewAndroid::OnPhysicalBackingSizeChanged(const gfx::Size& size) {
+  if (physical_size_ == size)
+    return;
+  physical_size_ = size;
+  client_->OnPhysicalBackingSizeChanged();
+
+  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(