Use calloc to allocate data that will be uploaded to vertex/index buffers in Chrome

src/gpu/gl/GrGLBufferImpl.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLBufferImpl.h"
 #include "GrGLGpu.h"
 
 #define GL_CALL(GPU, X) GR_GL_CALL(GPU->glInterface(), X)
 
 #ifdef SK_DEBUG
 #define VALIDATE() this->validate()
 #else
 #define VALIDATE() do {} while(false)
 #endif
 
 // GL_STREAM_DRAW triggers an optimization in Chromium's GPU process where a client's vertex buffer
 // objects are implemented as client-side-arrays on tile-deferred architectures.
 #define DYNAMIC_USAGE_PARAM GR_GL_STREAM_DRAW
 
 GrGLBufferImpl::GrGLBufferImpl(GrGLGpu* gpu, const Desc& desc, GrGLenum bufferType)
     : fDesc(desc)
     , fBufferType(bufferType)
     , fMapPtr(NULL) {
     if (0 == desc.fID) {
-        fCPUData = sk_malloc_flags(desc.fSizeInBytes, SK_MALLOC_THROW);
+        if (gpu->caps()->mustClearUploadedBufferData()) {
+            fCPUData = sk_calloc_throw(desc.fSizeInBytes);
+        } else {
+            fCPUData = sk_malloc_flags(desc.fSizeInBytes, SK_MALLOC_THROW);
+        }
         fGLSizeInBytes = 0;
     } else {
         fCPUData = NULL;
         // We assume that the GL buffer was created at the desc's size initially.
         fGLSizeInBytes = fDesc.fSizeInBytes;
     }
     VALIDATE();
 }
 
 void GrGLBufferImpl::release(GrGLGpu* gpu) {
@@ skipping 177 matching lines @@
 }
 
 void GrGLBufferImpl::validate() const {
     SkASSERT(GR_GL_ARRAY_BUFFER == fBufferType || GR_GL_ELEMENT_ARRAY_BUFFER == fBufferType);
     // The following assert isn't valid when the buffer has been abandoned:
     // SkASSERT((0 == fDesc.fID) == (fCPUData));
     SkASSERT(NULL == fCPUData || 0 == fGLSizeInBytes);
     SkASSERT(NULL == fMapPtr || fCPUData || fGLSizeInBytes == fDesc.fSizeInBytes);
     SkASSERT(NULL == fCPUData || NULL == fMapPtr || fCPUData == fMapPtr);
 }