Move memory observer off OutputSurface/CompositorFrameSink

cc/output/output_surface.h

Index: cc/output/output_surface.h
diff --git a/cc/output/output_surface.h b/cc/output/output_surface.h
index 9a3d8ce6802ebfcea3b4903fa6ac3a1cbe87957b..7c8e8782f712b9fca5a38153c14faeb4a349dfd0 100644
--- a/cc/output/output_surface.h
+++ b/cc/output/output_surface.h
@@ -12,7 +12,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
-#include "base/trace_event/memory_dump_provider.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/overlay_candidate_validator.h"
@@ -46,7 +45,7 @@ class OutputSurfaceFrame;
 //      From here on, it will only be used on the compositor thread.
 //   3. If the 3D context is lost, then the compositor will delete the output
 //      surface (on the compositor thread) and go back to step 1.
-class CC_EXPORT OutputSurface : public base::trace_event::MemoryDumpProvider {
+class CC_EXPORT OutputSurface {
  public:
   struct Capabilities {
     Capabilities() = default;
@@ -67,7 +66,7 @@ class CC_EXPORT OutputSurface : public base::trace_event::MemoryDumpProvider {
   explicit OutputSurface(
       scoped_refptr<VulkanContextProvider> vulkan_context_provider);
 
-  ~OutputSurface() override;
+  virtual ~OutputSurface();
 
   // Called by the compositor on the compositor thread. This is a place where
   // thread-specific data for the output surface can be initialized, since from
@@ -133,10 +132,6 @@ class CC_EXPORT OutputSurface : public base::trace_event::MemoryDumpProvider {
   // OutputSurfaceClient::DidSwapBuffersComplete() eventually.
   virtual void SwapBuffers(OutputSurfaceFrame frame) = 0;
 
-  // base::trace_event::MemoryDumpProvider implementation.
-  bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
-                    base::trace_event::ProcessMemoryDump* pmd) override;
-
  protected:
   void PostSwapBuffersComplete();