Add flag to force gpu trace markers to be used and printed out for debugging.

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLGpu.h"
 #include "GrGLStencilBuffer.h"
@@ skipping 2760 matching lines @@
             return true;
         }
     }
     return false;
 }
 
 void GrGLGpu::didAddGpuTraceMarker() {
     if (this->caps()->gpuTracingSupport()) {
         const GrTraceMarkerSet& markerArray = this->getActiveTraceMarkers();
         SkString markerString = markerArray.toStringLast();
+#if GR_FORCE_GPU_TRACE_DEBUGGING
+        SkDebugf("%s\n", markerString.c_str());
+#else
         GL_CALL(PushGroupMarker(0, markerString.c_str()));
+#endif
     }
 }
 
 void GrGLGpu::didRemoveGpuTraceMarker() {
     if (this->caps()->gpuTracingSupport()) {
+#if GR_FORCE_GPU_TRACE_DEBUGGING
+        SkDebugf("Pop trace marker.\n");
+#else
         GL_CALL(PopGroupMarker());
+#endif
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 GrGLAttribArrayState* GrGLGpu::HWGeometryState::bindArrayAndBuffersToDraw(
                                                 GrGLGpu* gpu,
                                                 const GrGLVertexBuffer* vbuffer,
                                                 const GrGLIndexBuffer* ibuffer) {
     SkASSERT(vbuffer);
@@ skipping 16 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }