Reland: GpuMemoryBuffer interface change: Map(**) to Map() and memory(plane); stride(plane)

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 "base/trace_event/memory_dump_manager.h"
 #include "build/build_config.h"
@@ skipping 12 matching lines @@
 
 enum GpuMemoryBufferType {
   EMPTY_BUFFER,
   SHARED_MEMORY_BUFFER,
   IO_SURFACE_BUFFER,
   SURFACE_TEXTURE_BUFFER,
   OZONE_NATIVE_PIXMAP,
   GPU_MEMORY_BUFFER_TYPE_LAST = OZONE_NATIVE_PIXMAP
 };
 
-using GpuMemoryBufferId = gfx::GenericSharedMemoryId;
+using GpuMemoryBufferId = GenericSharedMemoryId;
 
 struct GFX_EXPORT GpuMemoryBufferHandle {
   GpuMemoryBufferHandle();
   bool is_null() const { return type == EMPTY_BUFFER; }
   GpuMemoryBufferType type;
   GpuMemoryBufferId id;
   base::SharedMemoryHandle handle;
 #if defined(USE_OZONE)
   NativePixmapHandle native_pixmap_handle;
 #endif
 };
 
 base::trace_event::MemoryAllocatorDumpGuid GFX_EXPORT
 GetGpuMemoryBufferGUIDForTracing(uint64 tracing_process_id,
                                  GpuMemoryBufferId buffer_id);
 
 // This interface typically correspond to a type of shared memory that is also
 // shared with the GPU. A GPU memory buffer can be written to directly by
 // regular CPU code, but can also be read by the GPU.
 class GFX_EXPORT GpuMemoryBuffer {
  public:
   virtual ~GpuMemoryBuffer() {}
 
   // 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;
+  // 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 false on failure.
+  virtual bool Map() = 0;
 
-  // Unmaps the buffer. It's illegal to use the pointer returned by Map() after
-  // this has been called.
+  // Returns a pointer to the memory address of a plane. Buffer must have been
+  // successfully mapped using a call to Map() before calling this function.
+  virtual void* memory(size_t plane) = 0;
+
+  // Unmaps the buffer. It's illegal to use any pointer returned by memory()
+  // after this has been called.
   virtual void Unmap() = 0;
 
   // Returns the size for the buffer.
-  virtual gfx::Size GetSize() const = 0;
+  virtual Size GetSize() const = 0;
 
   // Returns the format for the buffer.
   virtual BufferFormat GetFormat() const = 0;
 
   // Fills the stride in bytes for each plane of the buffer. The stride of
   // plane K is stored at index K-1 of the |stride| array.
-  virtual void GetStride(int* stride) const = 0;
+  virtual int stride(size_t plane) const = 0;
 
   // Returns a unique identifier associated with buffer.
   virtual GpuMemoryBufferId GetId() 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_