tracing: remove WatchEvent feature

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 3f988e660a6536e9a4651ad4c13cf3655f050a7b..9c87927e3626143790c205e6d25eb28135765c60 100644
--- a/chrome/test/base/tracing.h
+++ b/chrome/test/base/tracing.h
@@ -29,15 +29,6 @@ namespace tracing {
 bool BeginTracing(const std::string& category_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& category_patterns,
-                           const std::string& category_name,
-                           const std::string& event_name,
-                           int num_occurrences) WARN_UNUSED_RESULT;
-
-// Called from UI thread.
 // Begin tracing specified category_patterns on the browser.
 // |trace_config| specifies the configuration for tracing. This includes the
 // list of categories enabled, tracing modes and memory dumps configuration.
@@ -47,12 +38,6 @@ bool BeginTracingWithTraceConfig(
     const base::trace_event::TraceConfig& trace_config) WARN_UNUSED_RESULT;
 
 // Called from UI thread.
-// Wait on the event set with BeginTracingWithWatch. If non-zero, return after
-// |timeout| regardless of watch event notification. Returns true if watch event
-// occurred, false if it timed out.
-bool WaitForWatchEvent(base::TimeDelta timeout) WARN_UNUSED_RESULT;
-
-// Called from UI thread.
 // End trace and collect the trace output as a json string.
 bool EndTracing(std::string* json_trace_output) WARN_UNUSED_RESULT;