Trace category groups and category filter.

content/browser/devtools/devtools_tracing_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/devtools/devtools_tracing_handler.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/json/json_writer.h"
 #include "base/location.h"
@@ skipping 42 matching lines @@
   if (is_running_) {
     base::DictionaryValue* params = new base::DictionaryValue();
     params->SetString("value", trace_fragment->data());
     SendNotification(kTracingDataCollected, params, NULL);
   }
 }
 
 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;
 }
 
 base::DictionaryValue* DevToolsTracingHandler::OnEnd(
     const base::DictionaryValue* params,
     base::Value** error_out) {
   TraceController::GetInstance()->EndTracingAsync(this);
   return NULL;
 }
 
 }  // namespace content