Revert 205970 "Revert 205481 "Virtual context MakeCurrent tweaks.""

trunk/src/content/common/gpu/image_transport_surface_mac.cc

Index: trunk/src/content/common/gpu/image_transport_surface_mac.cc
===================================================================
--- trunk/src/content/common/gpu/image_transport_surface_mac.cc	(revision 206118)
+++ trunk/src/content/common/gpu/image_transport_surface_mac.cc	(working copy)
@@ -6,6 +6,7 @@
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_ptr.h"
+#include "content/common/gpu/gpu_command_buffer_stub.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_bindings.h"
@@ -33,8 +34,10 @@
 
 // We are backed by an offscreen surface for the purposes of creating
 // a context, but use FBOs to render to texture backed IOSurface
-class IOSurfaceImageTransportSurface : public gfx::NoOpGLSurfaceCGL,
-                                       public ImageTransportSurface {
+class IOSurfaceImageTransportSurface
+    : public gfx::NoOpGLSurfaceCGL,
+      public ImageTransportSurface,
+      public GpuCommandBufferStub::DestructionObserver {
  public:
   IOSurfaceImageTransportSurface(GpuChannelManager* manager,
                                  GpuCommandBufferStub* stub,
@@ -62,6 +65,9 @@
   virtual void OnResize(gfx::Size size, float scale_factor) OVERRIDE;
   virtual void SetLatencyInfo(const ui::LatencyInfo&) OVERRIDE;
 
+  // GpuCommandBufferStub::DestructionObserver implementation.
+  virtual void OnWillDestroyStub() OVERRIDE;
+
  private:
   virtual ~IOSurfaceImageTransportSurface() OVERRIDE;
 
@@ -138,7 +144,6 @@
 }
 
 IOSurfaceImageTransportSurface::~IOSurfaceImageTransportSurface() {
-  Destroy();
 }
 
 bool IOSurfaceImageTransportSurface::Initialize() {
@@ -151,7 +156,14 @@
 
   if (!helper_->Initialize())
     return false;
-  return NoOpGLSurfaceCGL::Initialize();
+
+  if (!NoOpGLSurfaceCGL::Initialize()) {
+    helper_->Destroy();
+    return false;
+  }
+
+  helper_->stub()->AddDestructionObserver(this);
+  return true;
 }
 
 void IOSurfaceImageTransportSurface::Destroy() {
@@ -313,6 +325,11 @@
   latency_info_ = latency_info;
 }
 
+void IOSurfaceImageTransportSurface::OnWillDestroyStub() {
+  helper_->stub()->RemoveDestructionObserver(this);
+  Destroy();
+}
+
 void IOSurfaceImageTransportSurface::UnrefIOSurface() {
   // If we have resources to destroy, then make sure that we have a current
   // context which we can use to delete the resources.