Trace category groups and category filter.

chrome/test/automation/automation_proxy.h

Index: chrome/test/automation/automation_proxy.h
diff --git a/chrome/test/automation/automation_proxy.h b/chrome/test/automation/automation_proxy.h
index 7f426cceebe8e3d8433f20252b5bdfb6f42a78be..611afc2dace2eb5f6401351c4e413db5e75698b1 100644
--- a/chrome/test/automation/automation_proxy.h
+++ b/chrome/test/automation/automation_proxy.h
@@ -153,19 +153,21 @@ class AutomationProxy : public IPC::Listener, public AutomationMessageSender {
                        int timeout_ms,
                        std::string* response) WARN_UNUSED_RESULT;
 
-  // Begin tracing specified categories on the browser instance. Blocks until
+  // Begin tracing specified tag_patterns on the browser instance. Blocks until
   // browser acknowledges that tracing has begun (or failed if false is
-  // returned). |categories| is a comma-delimited list of category wildcards.
-  // A category can have an optional '-' prefix to make it an excluded category.
-  // Either all categories must be included or all must be excluded.
+  // returned). |tag_patterns| is a comma-delimited list of category tag
+  // wildcards.
+  // A tag pattern can have an optional '-' prefix to exclude categories that
+  // contain matching tags.
+  // Either all tag_patterns must be included or all must be excluded.
   //
   // Example: BeginTracing("test_MyTest*");
   // Example: BeginTracing("test_MyTest*,test_OtherStuff");
-  // Example: BeginTracing("-excluded_category1,-excluded_category2");
+  // Example: BeginTracing("-excluded_tag1,-excluded_tag2");
   //
   // See base/event_trace.h for documentation of included and excluded
-  // categories.
-  bool BeginTracing(const std::string& categories) WARN_UNUSED_RESULT;
+  // tag_patterns.
+  bool BeginTracing(const std::string& tag_patterns) WARN_UNUSED_RESULT;
 
   // End trace and collect the trace output as a json string.
   bool EndTracing(std::string* json_trace_output) WARN_UNUSED_RESULT;