exo: Recreate Surface resources on context lost.

components/exo/surface.h

Index: components/exo/surface.h
diff --git a/components/exo/surface.h b/components/exo/surface.h
index 45395e955a494fc394d52eda077c809ebbf545e3..ae8a9af21f84b5176fd1a014086c58a528ff8fb8 100644
--- a/components/exo/surface.h
+++ b/components/exo/surface.h
@@ -20,6 +20,7 @@
 #include "third_party/skia/include/core/SkRegion.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/aura/window.h"
+#include "ui/compositor/compositor.h"
 #include "ui/compositor/layer_owner_delegate.h"
 #include "ui/gfx/geometry/rect.h"
 
@@ -86,7 +87,8 @@ class SurfaceFactoryOwner : public base::RefCounted<SurfaceFactoryOwner>,
 
 // This class represents a rectangular area that is displayed on the screen.
 // It has a location, size and pixel contents.
-class Surface : public ui::LayerOwnerDelegate {
+class Surface : public ui::LayerOwnerDelegate,
+                public ui::ContextFactoryObserver {
  public:
   typedef void (*PropertyDeallocator)(int64_t value);
 
@@ -206,6 +208,9 @@ class Surface : public ui::LayerOwnerDelegate {
   // Overridden from ui::LayerOwnerDelegate:
   void OnLayerRecreated(ui::Layer* old_layer, ui::Layer* new_layer) override;
 
+  // Overridden from ui::ContextFactoryObserver.
+  void OnLostResources() override;
+
   void WillDraw(cc::SurfaceId surface_id);
 
   // Check whether this Surface and its children need to create new cc::Surface
@@ -265,6 +270,16 @@ class Surface : public ui::LayerOwnerDelegate {
   // Set SurfaceLayer contents to the current buffer.
   void SetSurfaceLayerContents(ui::Layer* layer);
 
+  // Updates current_resource_ with a new resource id corresponding to the
+  // contents of the attached buffer (or id 0, if no buffer is attached).
+  // UpdateSurface must be called afterwards to ensure the release callback
+  // will be called.
+  void CreateResource(bool for_commit);
+
+  // Updates the current Surface with a new frame referring to the resource in
+  // current_resource_.
+  void UpdateSurface(bool for_commit);
+
   int64_t SetPropertyInternal(const void* key,
                               const char* name,
                               PropertyDeallocator deallocator,
@@ -337,6 +352,8 @@ class Surface : public ui::LayerOwnerDelegate {
   // The buffer that is currently set as content of surface.
   base::WeakPtr<Buffer> current_buffer_;
 
+  bool frame_is_opaque_ = false;
+
   // The last resource that was sent to a surface.
   cc::TransferableResource current_resource_;