Add Gpu Tracing to Ganesh

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index 52a25b452796b87740eedcb094e1517189af5bad..5f964578569b52c4cf1c6b51b34e614e9f37fa9e 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -860,6 +860,11 @@ public:
     // Called by tests that draw directly to the context via GrDrawTarget
     void getTestTarget(GrTestTarget*);
 
+    // Functions for managing gpu trace markers
+    bool isGpuTracingEnabled() const { return fGpuTracingEnabled; }
+    void enableGpuTracing() { fGpuTracingEnabled = true; }
+    void disableGpuTracing() { fGpuTracingEnabled = false; }
+
     /**
      * Stencil buffers add themselves to the cache using addStencilBuffer. findStencilBuffer is
      * called to check the cache for a SB that matches an RT's criteria.
@@ -923,6 +928,8 @@ private:
 
     int                             fMaxTextureSizeOverride;
 
+    bool                            fGpuTracingEnabled;
+
     GrContext(); // init must be called after the constructor.
     bool init(GrBackend, GrBackendContext);