Improve gpu tracing when applying markers directly to gpu target

src/gpu/GrInOrderDrawBuffer.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 "GrInOrderDrawBuffer.h"
 
 #include "GrBufferAllocPool.h"
@@ skipping 577 matching lines @@
     StencilPathAllocator::Iter stencilPathIter(&fStencilPaths);
     DrawPathAllocator::Iter drawPathIter(&fDrawPath);
     DrawPathsAllocator::Iter drawPathsIter(&fDrawPaths);
     CopySurfaceAllocator::Iter copySurfaceIter(&fCopySurfaces);
 
     int currCmdMarker   = 0;
 
     fDstGpu->saveActiveTraceMarkers();
     for (int c = 0; c < numCmds; ++c) {
         GrGpuTraceMarker newMarker("", -1);
+        SkString traceString;
         if (cmd_has_trace_marker(fCmds[c])) {
-            SkString traceString = fGpuCmdMarkers[currCmdMarker].toString();
+            traceString = fGpuCmdMarkers[currCmdMarker].toString();
             newMarker.fMarker = traceString.c_str();
             fDstGpu->addGpuTraceMarker(&newMarker);
             ++currCmdMarker;
         }
         switch (strip_trace_bit(fCmds[c])) {
             case kDraw_Cmd: {
                 SkASSERT(fDstGpu->drawState() != prevDrawState);
                 SkAssertResult(drawIter.next());
                 fDstGpu->setVertexSourceToBuffer(drawIter->fVertexBuffer);
                 if (drawIter->isIndexed()) {
@@ skipping 377 matching lines @@
 GrInOrderDrawBuffer::CopySurface* GrInOrderDrawBuffer::recordCopySurface() {
     this->addToCmdBuffer(kCopySurface_Cmd);
     return &fCopySurfaces.push_back();
 }
 
 void GrInOrderDrawBuffer::clipWillBeSet(const GrClipData* newClipData) {
     INHERITED::clipWillBeSet(newClipData);
     fClipSet = true;
     fClipProxyState = kUnknown_ClipProxyState;
 }