Add builders for tracing event's structural arguments

cc/quads/io_surface_draw_quad.cc

Index: cc/quads/io_surface_draw_quad.cc
diff --git a/cc/quads/io_surface_draw_quad.cc b/cc/quads/io_surface_draw_quad.cc
index cc3581bd0833d7a35d3ceb1bdd52ff5955f4b48a..e565a43066b533fef8c0a873c13e64ccdd5cefc4 100644
--- a/cc/quads/io_surface_draw_quad.cc
+++ b/cc/quads/io_surface_draw_quad.cc
@@ -4,6 +4,7 @@
 
 #include "cc/quads/io_surface_draw_quad.h"
 
+#include "base/debug/trace_event_argument.h"
 #include "base/logging.h"
 #include "base/values.h"
 #include "cc/base/math_util.h"
@@ -56,8 +57,11 @@ const IOSurfaceDrawQuad* IOSurfaceDrawQuad::MaterialCast(
   return static_cast<const IOSurfaceDrawQuad*>(quad);
 }
 
-void IOSurfaceDrawQuad::ExtendValue(base::DictionaryValue* value) const {
-  value->Set("io_surface_size", MathUtil::AsValue(io_surface_size).release());
+void IOSurfaceDrawQuad::ExtendValue(base::debug::TracedValue* value) const {
+  value->BeginDictionary("io_surface_size");
+  MathUtil::AddToTracedValue(io_surface_size, value);
+  value->EndDictionary();
+
   value->SetInteger("io_surface_resource_id", io_surface_resource_id);
   const char* orientation_string = NULL;
   switch (orientation) {