Add trace event when GrBufferAllocPool unmaps a buffer indicating what % of the buffer was unwritte…

src/gpu/GrBufferAllocPool.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 GrBufferAllocPool_DEFINED
 #define GrBufferAllocPool_DEFINED
 
@@ skipping 137 matching lines @@
     friend class GrGpu;
     void releaseGpuRef();
 
     struct BufferBlock {
         size_t              fBytesFree;
         GrGeometryBuffer*   fBuffer;
     };
 
     bool createBlock(size_t requestSize);
     void destroyBlock();
-    void flushCpuData(GrGeometryBuffer* buffer, size_t flushSize);
+    void flushCpuData(const BufferBlock& block, size_t flushSize);
 #ifdef SK_DEBUG
     void validate(bool unusedBlockAllowed = false) const;
 #endif
 
     size_t                          fBytesInUse;
 
     GrGpu*                          fGpu;
     bool                            fGpuIsReffed;
     bool                            fFrequentResetHint;
     SkTDArray<GrGeometryBuffer*>    fPreallocBuffers;
@@ skipping 169 matching lines @@
      * @return number of indices that fit in one of the preallocated index
      *         buffers.
      */
     int preallocatedBufferIndices() const;
 
 private:
     typedef GrBufferAllocPool INHERITED;
 };
 
 #endif