cc: Add message passing mechanism to micro benchmarking.

cc/debug/unittest_only_benchmark.cc

Index: cc/debug/unittest_only_benchmark.cc
diff --git a/cc/debug/unittest_only_benchmark.cc b/cc/debug/unittest_only_benchmark.cc
index 9c6b17699e312c2bffe9408ab94e9fb79a60540a..0f0694ad9df3e25f01b4bb7e880eebc69b1968d6 100644
--- a/cc/debug/unittest_only_benchmark.cc
+++ b/cc/debug/unittest_only_benchmark.cc
@@ -36,6 +36,18 @@ void UnittestOnlyBenchmark::DidUpdateLayers(LayerTreeHost* host) {
   NotifyDone(scoped_ptr<base::Value>());
 }
 
+bool UnittestOnlyBenchmark::ProcessMessage(scoped_ptr<base::Value> value) {
+  base::DictionaryValue* message = NULL;
+  value->GetAsDictionary(&message);
+  bool can_handle;
+  if (message->HasKey("can_handle")) {
+    message->GetBoolean("can_handle", &can_handle);
+    if (can_handle)
+      return true;
+  }
+  return false;
+}
+
 void UnittestOnlyBenchmark::RecordImplResults(scoped_ptr<base::Value> results) {
   NotifyDone(results.Pass());
 }