Decouple VR Shell DPR and CSS size from Physical Displays.

chrome/browser/android/vr_shell/vr_compositor.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 "chrome/browser/android/vr_shell/vr_compositor.h"
 
 #include "cc/layers/layer.h"
 #include "content/public/browser/android/compositor.h"
 #include "content/public/browser/web_contents.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/android/window_android.h"
 
+using base::android::JavaParamRef;
+
 namespace vr_shell {
 
 VrCompositor::VrCompositor(ui::WindowAndroid* window, bool transparent)
     : background_color_(SK_ColorWHITE),
       transparent_(transparent) {
   compositor_.reset(content::Compositor::Create(this, window));
   compositor_->SetHasTransparentBackground(transparent);
 }
 
 VrCompositor::~VrCompositor() {
   if (layer_) {
     layer_->SetBackgroundColor(background_color_);
     if (layer_parent_) {
       layer_parent_->AddChild(layer_);
     }
   }
 }
 
 void VrCompositor::UpdateLayerTreeHost() {}
 
 void VrCompositor::OnSwapBuffersCompleted(int pending_swap_buffers) {}
 
 void VrCompositor::SetLayer(content::WebContents* web_contents) {
   assert(layer_ == nullptr);
   ui::ViewAndroid* view_android = web_contents->GetNativeView();
+
   // When we pass the layer for the ContentViewCore to the compositor it may be
   // removing it from its previous parent, so we remember that and restore it to
   // its previous parent on teardown.
   layer_ = view_android->GetLayer();
 
   // Remember the old background color to be restored later.
   background_color_ = layer_->background_color();
   if (transparent_) {
     layer_->SetBackgroundColor(SK_ColorTRANSPARENT);
   }
   layer_parent_ = layer_->parent();
   compositor_->SetRootLayer(layer_);
 }
 
 void VrCompositor::SurfaceDestroyed() {
   compositor_->SetSurface(nullptr);
 }
 
-void VrCompositor::SurfaceChanged(
-    int width,
-    int height,
-    const base::android::JavaParamRef<jobject>& surface) {
-  DCHECK(surface);
-  compositor_->SetSurface(surface);
+void VrCompositor::SetWindowBounds(int width, int height) {
   compositor_->SetWindowBounds(gfx::Size(width, height));
 }
 
+void VrCompositor::SurfaceChanged(const JavaParamRef<jobject>& surface) {
+  DCHECK(surface);
+  compositor_->SetSurface(surface);
+}
+
 }  // namespace vr_shell