Add multi-planar functions to GpuMemoryBuffer

ui/gfx/gpu_memory_buffer.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_GPU_MEMORY_BUFFER_H_
 #define UI_GFX_GPU_MEMORY_BUFFER_H_
 
 #include "base/memory/shared_memory.h"
 #include "build/build_config.h"
 #include "ui/gfx/gfx_export.h"
@@ skipping 43 matching lines @@
 
     FORMAT_LAST = BGRA_8888
   };
 
   // The usage mode affects how a buffer can be used. Only buffers created with
   // MAP can be mapped into the client's address space and accessed by the CPU.
   enum Usage { MAP, SCANOUT, USAGE_LAST = SCANOUT };
 
   virtual ~GpuMemoryBuffer() {}
 
-  // Maps the buffer into the client's address space so it can be written to by
-  // the CPU. This call may block, for instance if the GPU needs to finish
-  // accessing the buffer or if CPU caches need to be synchronized. Returns NULL
-  // on failure.
-  virtual void* Map() = 0;
+  // Maps each plane of the buffer into the client's address space so it can be
+  // written to by the CPU. A pointer to plane K is stored at index K-1 of the
+  // |data| array. This call may block, for instance if the GPU needs to finish
+  // accessing the buffer or if CPU caches need to be synchronized. Returns
+  // false on failure.
+  virtual bool Map(void** data) = 0;
 
   // Unmaps the buffer. It's illegal to use the pointer returned by Map() after
   // this has been called.
   virtual void Unmap() = 0;
 
   // Returns true iff the buffer is mapped.
   virtual bool IsMapped() const = 0;
 
   // Returns the format for the buffer.
   virtual Format GetFormat() const = 0;
 
-  // Returns the stride in bytes for the buffer.
-  virtual uint32 GetStride() const = 0;
+  // Fills the stride in bytes for the each plane of the buffer. The stride of
+  // plane K is stored at index K-1 of the |stride| array.
+  virtual void GetStride(uint32* stride) const = 0;
 
   // Returns a platform specific handle for this buffer.
   virtual GpuMemoryBufferHandle GetHandle() const = 0;
 
   // Type-checking downcast routine.
   virtual ClientBuffer AsClientBuffer() = 0;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GPU_MEMORY_BUFFER_H_