Trace category groups and category filter.

chrome/test/base/tracing.h

Index: chrome/test/base/tracing.h
diff --git a/chrome/test/base/tracing.h b/chrome/test/base/tracing.h
index 15dffc7bf65ef1d82537a0eec1a3165a34575541..1589c037cbd3f43376f01b26dc659e8631f5a2b0 100644
--- a/chrome/test/base/tracing.h
+++ b/chrome/test/base/tracing.h
@@ -13,24 +13,25 @@
 namespace tracing {
 
 // Called from UI thread.
-// Begin tracing specified categories on the browser.
-// |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.
+// Begin tracing specified tag_patterns on the browser.
+// |tag_patterns| is a comma-delimited list of category tag wildcards.
+// A tag pattern can have an optional '-' prefix to make  categories with
+// matching tags excluded. 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/debug/trace_event.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;
 
 // Called from UI thread.
 // Specify a watch event in order to use the WaitForWatchEvent function.
 // After |num_occurrences| of the given event have been seen on a particular
 // process, WaitForWatchEvent will return.
-bool BeginTracingWithWatch(const std::string& categories,
+bool BeginTracingWithWatch(const std::string& tag_patterns,
                            const std::string& category_name,
                            const std::string& event_name,
                            int num_occurrences) WARN_UNUSED_RESULT;