Added GL_CHROMIUM_trace_marker feature as well as gpu_toplevel markers.

base/debug/trace_event.h

Index: base/debug/trace_event.h
diff --git a/base/debug/trace_event.h b/base/debug/trace_event.h
index 62a9b1f047a4b24d49cf4e14c3325120d39f25b6..58d55ddd653068c5e9f2770b1b25db7abcc9a010 100644
--- a/base/debug/trace_event.h
+++ b/base/debug/trace_event.h
@@ -788,6 +788,17 @@
         (base::debug::TraceLog::ENABLED_FOR_RECORDING | \
          base::debug::TraceLog::ENABLED_FOR_EVENT_CALLBACK))
 
+// Macros to track GPU timings much like the CPU variants.
+#define TRACE_GPU_EVENT_BEGIN0(context, category_group, name) \
+    do { \
+      context->TraceBeginCHROMIUM(category_group, name); \

[vmiura, 2014/12/09 00:18:10]

I think we should check if the category is enabled here, and in the END0.

if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE()) {
 ...
}

+    } while (0)
+
+#define TRACE_GPU_EVENT_END0(context) \
+    do { \
+      context->TraceEndCHROMIUM(); \
+    } while (0)
+
 // Macro to efficiently determine if a given category group is enabled.
 #define TRACE_EVENT_CATEGORY_GROUP_ENABLED(category_group, ret) \
     do { \