Add generated and hand-written passthrough command handlers with stub Doers.

gpu/command_buffer/common/buffer.h

 // Copyright (c) 2014 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 GPU_COMMAND_BUFFER_COMMON_BUFFER_H_
 #define GPU_COMMAND_BUFFER_COMMON_BUFFER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 38 matching lines @@
  public:
   explicit Buffer(std::unique_ptr<BufferBacking> backing);
 
   BufferBacking* backing() const { return backing_.get(); }
   void* memory() const { return memory_; }
   size_t size() const { return size_; }
 
   // Returns NULL if the address overflows the memory.
   void* GetDataAddress(uint32_t data_offset, uint32_t data_size) const;
 
+  // Returns NULL if the address overflows the memory.
+  void* GetDataAddressAndSize(uint32_t data_offset, uint32_t* data_size) const;
+
+  // Returns the remaining size of the buffer after an offset
+  uint32_t GetRemainingSize(uint32_t data_offset) const;
+
  private:
   friend class base::RefCountedThreadSafe<Buffer>;
   ~Buffer();
 
   std::unique_ptr<BufferBacking> backing_;
   void* memory_;
   size_t size_;
 
   DISALLOW_COPY_AND_ASSIGN(Buffer);
 };
@@ skipping 13 matching lines @@
 }
 
 // Generates GUID which can be used to trace buffer using an Id.
 GPU_EXPORT base::trace_event::MemoryAllocatorDumpGuid GetBufferGUIDForTracing(
     uint64_t tracing_process_id,
     int32_t buffer_id);
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_BUFFER_H_