Allow gpu debug markers to be placed by using a GrContext

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index acf146f575ab64f011b456af7a732fd06778ad3f..608ec507b2919e910ae477b325888dca01e5e52d 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -26,6 +26,7 @@ class GrDrawTarget;
 class GrEffect;
 class GrFontCache;
 class GrGpu;
+class GrGpuTraceMarker;
 class GrIndexBuffer;
 class GrIndexBufferAllocPool;
 class GrInOrderDrawBuffer;
@@ -925,6 +926,9 @@ public:
     void enableGpuTracing() { fGpuTracingEnabled = true; }
     void disableGpuTracing() { fGpuTracingEnabled = false; }
 
+    void addGpuTraceMarker(const GrGpuTraceMarker* marker);
+    void removeGpuTraceMarker(const GrGpuTraceMarker* marker);
+
     /**
      * 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.