Added a unique command buffer ID for command buffers.

gpu/command_buffer/common/constants.h

Index: gpu/command_buffer/common/constants.h
diff --git a/gpu/command_buffer/common/constants.h b/gpu/command_buffer/common/constants.h
index d06836c0d71ea9e5a5c871db8ef79f75ea424eca..0b312eded1eec448a9104018849fc7c6ae435f50 100644
--- a/gpu/command_buffer/common/constants.h
+++ b/gpu/command_buffer/common/constants.h
@@ -66,6 +66,18 @@ const int32_t kCommandBufferSharedMemoryId = 4;
 // The size to set for the program cache.
 const size_t kDefaultMaxProgramCacheMemoryBytes = 6 * 1024 * 1024;
 
+// Namespace used to separate various command buffer types.
+enum CommandBufferNamespace {
+  kCommandBufferNamespace_Invalid = -1,

[dcheng, 2015/09/17 17:08:18]

Chrome enum naming convention is to NAME_LIKE_THIS.

Also consider just using enum class.

[David Yen, 2015/09/17 17:26:21]

Done.

+
+  kCommandBufferNamespace_GpuIO,
+  kCommandBufferNamespace_InProcess,
+  kCommandBufferNamespace_Mojo,
+
+  NUM_COMMAND_BUFFER_NAMESPACES

[dcheng, 2015/09/17 17:08:18]

Is this actually used for anything?

[David Yen, 2015/09/17 17:26:21]

The background of this patch is that it was moved out of another CL because
erick@ also needed to identify command buffers. The
NUM_COMMAND_BUFFER_NAMESPACES is used to declare an array for each namespace in
that patch:
(https://codereview.chromium.org/1339203002/diff/60001/gpu/command_buffer/serv...)

+};
+
+
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_CONSTANTS_H_