Added a unique command buffer ID for command buffers.

gpu/command_buffer/service/in_process_command_buffer.cc

Index: gpu/command_buffer/service/in_process_command_buffer.cc
diff --git a/gpu/command_buffer/service/in_process_command_buffer.cc b/gpu/command_buffer/service/in_process_command_buffer.cc
index 6997cecdbf2de82fd668b4f7155050e5790e0727..2b34b2e453f041aedd4be5cb2cda61e25477f9cc 100644
--- a/gpu/command_buffer/service/in_process_command_buffer.cc
+++ b/gpu/command_buffer/service/in_process_command_buffer.cc
@@ -54,6 +54,8 @@ namespace gpu {
 
 namespace {
 
+base::StaticAtomicSequenceNumber g_next_command_buffer_id;
+
 template <typename T>
 static void RunTaskWithResult(base::Callback<T(void)> task,
                               T* result,
@@ -174,7 +176,8 @@ gpu::gles2::ProgramCache* InProcessCommandBuffer::Service::program_cache() {
 
 InProcessCommandBuffer::InProcessCommandBuffer(
     const scoped_refptr<Service>& service)
-    : context_lost_(false),
+    : command_buffer_id_(g_next_command_buffer_id.GetNext()),
+      context_lost_(false),
       idle_work_pending_(false),
       image_factory_(nullptr),
       last_put_offset_(-1),
@@ -845,6 +848,14 @@ bool InProcessCommandBuffer::IsGpuChannelLost() {
   return false;
 }
 
+CommandBufferNamespace InProcessCommandBuffer::GetNamespaceID() const {
+  return kCommandBufferNamespace_InProcess;
+}
+
+uint64_t InProcessCommandBuffer::GetCommandBufferID() const {
+  return command_buffer_id_;
+}
+
 uint32 InProcessCommandBuffer::CreateStreamTextureOnGpuThread(
     uint32 client_texture_id) {
 #if defined(OS_ANDROID)