Android: Don't destroy LayerTreeHost when Surface goes away

content/browser/renderer_host/compositor_impl_android.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_COMPOSITOR_IMPL_ANDROID_H_
 #define CONTENT_BROWSER_RENDERER_HOST_COMPOSITOR_IMPL_ANDROID_H_
 
 #include "base/basictypes.h"
 #include "base/cancelable_callback.h"
 #include "base/compiler_specific.h"
@@ skipping 25 matching lines @@
 namespace content {
 class CompositorClient;
 
 // -----------------------------------------------------------------------------
 // Browser-side compositor that manages a tree of content and UI layers.
 // -----------------------------------------------------------------------------
 class CONTENT_EXPORT CompositorImpl
     : public Compositor,
       public cc::LayerTreeHostClient,
       public cc::LayerTreeHostSingleThreadClient,
+      public ui::UIResourceProvider,
       public ui::WindowAndroidCompositor {
  public:
   class VSyncObserver {
    public:
     virtual void OnUpdateVSyncParameters(base::TimeTicks timebase,
                                          base::TimeDelta interval) = 0;
   };
 
   CompositorImpl(CompositorClient* client, gfx::NativeWindow root_window);
   ~CompositorImpl() override;
 
   static bool IsInitialized();
 
   static cc::SurfaceManager* GetSurfaceManager();
   static scoped_ptr<cc::SurfaceIdAllocator> CreateSurfaceIdAllocator();
 
   void PopulateGpuCapabilities(gpu::Capabilities gpu_capabilities);
 
   void AddObserver(VSyncObserver* observer);
   void RemoveObserver(VSyncObserver* observer);
 
+  // ui::ResourceProvider implementation.
+  cc::UIResourceId CreateUIResource(cc::UIResourceClient* client) final;

[jdduke (slow), 2015/09/30 17:19:43]

Should this be "final override"? Do we have any guidance on preferring
"override" vs "final override"? Seems like most of our codebase intends the
latter semantics, but just uses "override".

[no sievers, 2015/09/30 21:58:47]

Done.

+  void DeleteUIResource(cc::UIResourceId resource_id) final;
+  bool SupportsETC1NonPowerOfTwo() const final;
+
  private:
   // Compositor implementation.
   void SetRootLayer(scoped_refptr<cc::Layer> root) override;
   void SetSurface(jobject surface) override;
   void setDeviceScaleFactor(float factor) override;
   void SetWindowBounds(const gfx::Size& size) override;
   void SetHasTransparentBackground(bool flag) override;
   void SetNeedsComposite() override;
   ui::UIResourceProvider& GetUIResourceProvider() override;
   ui::ResourceManager& GetResourceManager() override;
@@ skipping 72 matching lines @@
 
   void OnGpuChannelEstablished();
   void OnGpuChannelTimeout();
 
   // root_layer_ is the persistent internal root layer, while subroot_layer_
   // is the one attached by the compositor client.
   scoped_refptr<cc::Layer> root_layer_;
   scoped_refptr<cc::Layer> subroot_layer_;
 
   scoped_ptr<cc::LayerTreeHost> host_;
-  ui::UIResourceProvider ui_resource_provider_;
   ui::ResourceManagerImpl resource_manager_;
 
   scoped_ptr<cc::OnscreenDisplayClient> display_client_;
   scoped_ptr<cc::SurfaceIdAllocator> surface_id_allocator_;
 
   gfx::Size size_;
   bool has_transparent_background_;
   float device_scale_factor_;
 
   ANativeWindow* window_;
@@ skipping 36 matching lines @@
   base::TimeTicks last_vsync_;
 
   base::OneShotTimer establish_gpu_channel_timeout_;
 
   // Whether there is an OutputSurface request pending from the current
   // |host_|. Becomes |true| if RequestNewOutputSurface is called, and |false|
   // if |host_| is deleted or we succeed in creating *and* initializing an
   // OutputSurface (which is essentially the contract with cc).
   bool output_surface_request_pending_;
 
+  gpu::Capabilities gpu_capabilities_;
+
   base::ObserverList<VSyncObserver, true> observer_list_;
 
   base::WeakPtrFactory<CompositorImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CompositorImpl);
 };
 
 } // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_COMPOSITOR_IMPL_ANDROID_H_