Add hooks for GL_EXT_debug_marker in gpu

src/gpu/GrInOrderDrawBuffer.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrInOrderDrawBuffer_DEFINED
 #define GrInOrderDrawBuffer_DEFINED
 
@@ skipping 58 matching lines @@
     // overrides from GrDrawTarget
     virtual bool geometryHints(int* vertexCount,
                                int* indexCount) const SK_OVERRIDE;
     virtual void clear(const SkIRect* rect,
                        GrColor color,
                        bool canIgnoreRect,
                        GrRenderTarget* renderTarget = NULL) SK_OVERRIDE;
 
     virtual void initCopySurfaceDstDesc(const GrSurface* src, GrTextureDesc* desc) SK_OVERRIDE;
 
+    virtual void insertEventMarker(const char* marker) SK_OVERRIDE;
+    virtual void pushGroupMarker(const char* marker) SK_OVERRIDE;
+    virtual void popGroupMarker() SK_OVERRIDE;
+
 protected:
     virtual void clipWillBeSet(const GrClipData* newClip) SK_OVERRIDE;
 
 private:
     enum Cmd {
         kDraw_Cmd           = 1,
         kStencilPath_Cmd    = 2,
         kSetState_Cmd       = 3,
         kSetClip_Cmd        = 4,
         kClear_Cmd          = 5,
@@ skipping 151 matching lines @@
 
     virtual bool       isIssued(uint32_t drawID) { return drawID != fDrawID; }
 
     bool                            fFlushing;
     uint32_t                        fDrawID;
 
     typedef GrDrawTarget INHERITED;
 };
 
 #endif