Revert of Add a mutex to GrContext::readSurfacePixels to protect against multiple CPU raster threads accessin…

include/gpu/GrContext.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 
 #include "GrClip.h"
 #include "GrColor.h"
 #include "GrPaint.h"
 #include "GrPathRendererChain.h"
 #include "GrRenderTarget.h"
 #include "GrTextureProvider.h"
 #include "SkMatrix.h"
-#include "SkMutex.h"
 #include "SkPathEffect.h"
 #include "SkTypes.h"
 
 struct GrBatchAtlasConfig;
 class GrBatchFontCache;
 class GrCaps;
 struct GrContextOptions;
 class GrDrawContext;
 class GrDrawTarget;
 class GrFragmentProcessor;
@@ skipping 345 matching lines @@
     SkAutoTDelete<GrTextBlobCache>  fTextBlobCache;
 
     GrPathRendererChain*            fPathRendererChain;
     GrSoftwarePathRenderer*         fSoftwarePathRenderer;
 
     // Set by OverbudgetCB() to request that GrContext flush before exiting a draw.
     bool                            fFlushToReduceCacheSize;
     bool                            fDidTestPMConversions;
     int                             fPMToUPMConversion;
     int                             fUPMToPMConversion;
-    // The sw backend may call GrContext::readSurfacePixels on multiple threads
-    // We may transfer the responsibilty for using a mutex to the sw backend
-    // when there are fewer code paths that lead to a readSurfacePixels call
-    // from the sw backend.
-    SkMutex                         fReadPixelsMutex;
 
     struct CleanUpData {
         PFCleanUpFunc fFunc;
         void*         fInfo;
     };
 
     SkTDArray<CleanUpData>          fCleanUpData;
 
     const uint32_t                  fUniqueID;
 
@@ skipping 69 matching lines @@
     /**
      * A callback similar to the above for use by the TextBlobCache
      * TODO move textblob draw calls below context so we can use the call above.
      */
     static void TextBlobCacheOverBudgetCB(void* data);
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif