Add layer name into frame viewer

cc/layers/content_layer.cc

Index: cc/layers/content_layer.cc
diff --git a/cc/layers/content_layer.cc b/cc/layers/content_layer.cc
index e8db60b937c578ffc72de1e282eadf1adc2c659f..691eed81154f1b68a2c4845f0b1cc00252bc13a3 100644
--- a/cc/layers/content_layer.cc
+++ b/cc/layers/content_layer.cc
@@ -5,6 +5,7 @@
 #include "cc/layers/content_layer.h"
 
 #include "base/auto_reset.h"
+#include "base/debug/trace_event.h"
 #include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "cc/layers/content_layer_client.h"
@@ -78,6 +79,13 @@ void ContentLayer::Update(ResourceUpdateQueue* queue,
     UpdateCanUseLCDText();
   }
 
+  bool is_tracing;
+  TRACE_EVENT_CATEGORY_GROUP_ENABLED("cc", &is_tracing);
+  if (is_tracing)
+    SetDebugName(DebugName());
+  else
+    SetDebugName(std::string());
+
   TiledLayer::Update(queue, occlusion, stats);
   needs_display_ = false;
 }
@@ -132,4 +140,8 @@ bool ContentLayer::SupportsLCDText() const {
   return true;
 }
 
+std::string ContentLayer::DebugName() {
+  return client_->DebugName();
+}
+
 }  // namespace cc