Trace category groups and category filter.

content/browser/devtools/devtools_tracing_handler.cc

Index: content/browser/devtools/devtools_tracing_handler.cc
diff --git a/content/browser/devtools/devtools_tracing_handler.cc b/content/browser/devtools/devtools_tracing_handler.cc
index 7dc68c40b2cf012b83cf3172f16abbe1ded26a67..bda522101ff687b91575c20f97d5a9647934c9b5 100644
--- a/content/browser/devtools/devtools_tracing_handler.cc
+++ b/content/browser/devtools/devtools_tracing_handler.cc
@@ -60,10 +60,10 @@ void DevToolsTracingHandler::OnTraceDataCollected(
 base::DictionaryValue* DevToolsTracingHandler::OnStart(
     const base::DictionaryValue* params,
     base::Value** error_out) {
-  std::string categories;
+  std::string tag_patterns;
   if (params && params->HasKey(kCategoriesParam))

[rterrazas, 2013/01/18 01:22:05]

I believe the value of kCategoriesParam comes from trace-event-viewer correct?,
do you think we'd need to change it to "tag_patterns" for consistency?, thinking
yes, but I'd rather ask.

[rterrazas, 2013/01/21 06:59:53]

Duh, I was wrong, it seems like this stuff was introduced here:
https://chromiumcodereview.appspot.com/11548032

However, I can't find a call to SetString for kCategoriesParam nor "categories"
which leads me to believe that maybe that isn't implemented yet?, does this
sound right?.

-    params->GetString(kCategoriesParam, &categories);
-  TraceController::GetInstance()->BeginTracing(this, categories);
+    params->GetString(kCategoriesParam, &tag_patterns);
+  TraceController::GetInstance()->BeginTracing(this, tag_patterns);
   is_running_ = true;
   return NULL;
 }