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

include/gpu/GrCaps.h

Index: include/gpu/GrCaps.h
diff --git a/include/gpu/GrCaps.h b/include/gpu/GrCaps.h
index c9530d3720457f2890020d0b373476bf8f907013..48bcb28c4dfa21db368dbc6124126f1aaddea835 100644
--- a/include/gpu/GrCaps.h
+++ b/include/gpu/GrCaps.h
@@ -218,6 +218,10 @@ public:
 
     bool fullClearIsFree() const { return fFullClearIsFree; }
 
+    /** True in environments that will issue errors if memory uploaded to buffers 
+        is not initialized (even if not read by draw calls). */
+    bool mustClearUploadedBufferData() const { return fMustClearUploadedBufferData; }
+
 protected:
     /** Subclasses must call this at the end of their constructors in order to apply caps
         overrides requested by the client. Note that overrides will only reduce the caps never
@@ -239,6 +243,7 @@ protected:
     bool fTextureBarrierSupport                      : 1;
     bool fSupportsInstancedDraws                     : 1;
     bool fFullClearIsFree                            : 1;
+    bool fMustClearUploadedBufferData                : 1;
 
     // Driver workaround
     bool fUseDrawInsteadOfClear                      : 1;