VR: Remove unnecessary transparency support from VR compositor.

Just a cleanup patch, no change in functionality.

BUG=

Review-Url: https://codereview.chromium.org/2843993002
Cr-Commit-Position: refs/heads/master@{#467702}

chrome/browser/android/vr_shell/vr_compositor.cc

@@ -15,10 +15,8 @@
 
 namespace vr_shell {
 
-VrCompositor::VrCompositor(ui::WindowAndroid* window, bool transparent)
-    : background_color_(SK_ColorWHITE), transparent_(transparent) {
+VrCompositor::VrCompositor(ui::WindowAndroid* window) {
   compositor_.reset(content::Compositor::Create(this, window));
-  compositor_->SetHasTransparentBackground(transparent);
 }
 
 VrCompositor::~VrCompositor() {
@@ -39,24 +37,15 @@ void VrCompositor::SetLayer(content::WebContents* web_contents) {
   // 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::RestoreLayer() {
-  if (!layer_)
-    return;
-  layer_->SetBackgroundColor(background_color_);
-  if (layer_parent_) {
+  if (layer_ && layer_parent_)
     layer_parent_->AddChild(layer_);
-  }
   layer_ = nullptr;
+  layer_parent_ = nullptr;
 }
 
 void VrCompositor::SurfaceDestroyed() {

chrome/browser/android/vr_shell/vr_compositor.h

@@ -31,7 +31,7 @@ namespace vr_shell {
 
 class VrCompositor : public content::CompositorClient {
  public:
-  VrCompositor(ui::WindowAndroid* window, bool is_transparent);
+  explicit VrCompositor(ui::WindowAndroid* window);
   ~VrCompositor() override;
 
   void SurfaceDestroyed();
@@ -46,8 +46,6 @@ class VrCompositor : public content::CompositorClient {
 
   cc::Layer* layer_ = nullptr;
   cc::Layer* layer_parent_ = nullptr;
-  SkColor background_color_;
-  bool transparent_;
 
   DISALLOW_COPY_AND_ASSIGN(VrCompositor);
 };

chrome/browser/android/vr_shell/vr_shell.cc

@@ -88,7 +88,7 @@ VrShell::VrShell(JNIEnv* env,
                  bool reprojected_rendering)
     : vr_shell_enabled_(base::FeatureList::IsEnabled(features::kVrShell)),
       window_(window),
-      compositor_(base::MakeUnique<VrCompositor>(window_, false)),
+      compositor_(base::MakeUnique<VrCompositor>(window_)),
       delegate_provider_(delegate),
       main_thread_task_runner_(base::ThreadTaskRunnerHandle::Get()),
       reprojected_rendering_(reprojected_rendering),