gpu: Implement the new fence syncs in mojo command buffer.

mojo/gles2/command_buffer_client_impl.cc

Index: mojo/gles2/command_buffer_client_impl.cc
diff --git a/mojo/gles2/command_buffer_client_impl.cc b/mojo/gles2/command_buffer_client_impl.cc
index c6990b26e3f3bc16b2e4907a94489ac4e7c7f0ae..a4445e63d38dcd18c43e4ab78e69c5c20b19a71f 100644
--- a/mojo/gles2/command_buffer_client_impl.cc
+++ b/mojo/gles2/command_buffer_client_impl.cc
@@ -53,7 +53,9 @@ class CommandBufferClientImpl::SyncClientImpl
  public:
   SyncClientImpl(mus::mojom::CommandBufferSyncClientPtr* ptr,
                  const MojoAsyncWaiter* async_waiter)
-      : initialized_successfully_(false), binding_(this, ptr, async_waiter) {}
+      : initialized_successfully_(false),
+        command_buffer_id_(0),
+        binding_(this, ptr, async_waiter) {}
 
   bool WaitForInitialization() {
     if (!binding_.WaitForIncomingMethodCall())
@@ -73,11 +75,19 @@ class CommandBufferClientImpl::SyncClientImpl
     return gpu::Capabilities();
   }
 
+  uint64_t GetCommandBufferID() const {
+    return command_buffer_id_;
+  }
+
  private:
   // CommandBufferSyncClient methods:
   void DidInitialize(bool success,
+                     int32_t command_buffer_namespace,
+                     uint64_t command_buffer_id,
                      mus::mojom::GpuCapabilitiesPtr capabilities) override {
+    CHECK_EQ(command_buffer_namespace, gpu::CommandBufferNamespace::MOJO);
     initialized_successfully_ = success;
+    command_buffer_id_ = command_buffer_id;
     capabilities_ = capabilities.Pass();
   }
   void DidMakeProgress(mus::mojom::CommandBufferStatePtr state) override {
@@ -85,6 +95,7 @@ class CommandBufferClientImpl::SyncClientImpl
   }
 
   bool initialized_successfully_;
+  uint64_t command_buffer_id_;
   mus::mojom::GpuCapabilitiesPtr capabilities_;
   mus::mojom::CommandBufferStatePtr command_buffer_state_;
   mojo::Binding<mus::mojom::CommandBufferSyncClient> binding_;
@@ -403,11 +414,7 @@ gpu::CommandBufferNamespace CommandBufferClientImpl::GetNamespaceID() const {
 }
 
 uint64_t CommandBufferClientImpl::GetCommandBufferID() const {
-  // TODO (rjkroege): This must correspond to the command buffer ID on the
-  // server side. Most likely a combination of the client-specific integer and
-  // the connect id.
-  NOTIMPLEMENTED();
-  return 0;
+  return sync_client_impl_->GetCommandBufferID();
 }
 
 uint64_t CommandBufferClientImpl::GenerateFenceSyncRelease() {