Use mapped memory for uploading large textures.

gpu/command_buffer/client/mapped_memory.h

Index: gpu/command_buffer/client/mapped_memory.h
diff --git a/gpu/command_buffer/client/mapped_memory.h b/gpu/command_buffer/client/mapped_memory.h
index 10ac639929f3664a15d425c9b8fb82f46d331e1a..767bac7d0062ce3a0d7884c48e1c035950fe488f 100644
--- a/gpu/command_buffer/client/mapped_memory.h
+++ b/gpu/command_buffer/client/mapped_memory.h
@@ -199,6 +199,66 @@ class GPU_EXPORT MappedMemoryManager {
   DISALLOW_COPY_AND_ASSIGN(MappedMemoryManager);
 };
 
+// A class that will manage the lifetime of a mapped memory allocation
+class GPU_EXPORT ScopedMappedMemoryPtr {
+ public:
+  ScopedMappedMemoryPtr(
+      uint32_t size,
+      CommandBufferHelper* helper,
+      MappedMemoryManager* mapped_memory_manager)
+      : buffer_(NULL),
+        size_(0),
+        shm_id_(0),
+        shm_offset_(0),
+        flush_after_release_(false),
+        helper_(helper),
+        mapped_memory_manager_(mapped_memory_manager) {
+    Reset(size);
+  }
+
+  ~ScopedMappedMemoryPtr() {
+    Release();
+  }
+
+  bool valid() const {
+    return buffer_ != NULL;
+  }
+
+  void SetFlushAfterRelease(bool flush_after_release) {
+    flush_after_release_ = flush_after_release;
+  }
+
+  uint32_t size() const {
+    return size_;
+  }
+
+  int32_t shm_id() const {
+    return shm_id_;
+  }
+
+  uint32_t offset() const {
+    return shm_offset_;
+  }
+
+  void* address() const {
+    return buffer_;
+  }
+
+  void Release();
+
+  void Reset(uint32_t new_size);
+
+ private:
+  void* buffer_;
+  uint32_t size_;
+  int32_t shm_id_;
+  uint32_t shm_offset_;
+  bool flush_after_release_;
+  CommandBufferHelper* helper_;
+  MappedMemoryManager* mapped_memory_manager_;
+  DISALLOW_COPY_AND_ASSIGN(ScopedMappedMemoryPtr);
+};
+
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_