Improve gpu tracing when applying markers directly to gpu target

src/gpu/gl/GrGpuGL.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 "GrGpuGL.h"
 #include "GrGLNameAllocator.h"
@@ skipping 2964 matching lines @@
         } else {
             return true;
         }
     }
     return INHERITED::onCanCopySurface(dst, src, srcRect, dstPoint);
 }
 
 void GrGpuGL::didAddGpuTraceMarker() {
     if (this->caps()->gpuTracingSupport()) {
         const GrTraceMarkerSet& markerArray = this->getActiveTraceMarkers();
-        SkString markerString = markerArray.toString();
+        SkString markerString = markerArray.toStringLast();
         GL_CALL(PushGroupMarker(0, markerString.c_str()));
     }
 }
 
 void GrGpuGL::didRemoveGpuTraceMarker() {
     if (this->caps()->gpuTracingSupport()) {
         GL_CALL(PopGroupMarker());
     }
 }
 ///////////////////////////////////////////////////////////////////////////////
@@ skipping 22 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }