Fix --trace-startup.

Some subprocesses handle --trace-startup by themselves to start
tracing as early as possible if the switch presents. However, previously
TraceController would enable tracing of the subprocess again by sending
TracingMsg_BeginTracing when it knew a new subprocess has been started.
This caused tracing of the subprocess not to be properly stopped and
flushed when startup tracing is ended.

Changes:
- Pass tracing_startup parameter through TracingMsg_BeginTracing;
  subprocess won't start tracing again if tracing_startup is true
  and tracing has already been started;
- Don't pass --trace-startup to renderer if startup tracing has
  already finished.

BUG=310395

Review URL: https://codereview.chromium.org/48903003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231971 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 2 deletions

diff --git a/components/tracing/tracing_messages.h b/components/tracing/tracing_messages.h
index 25b45bd..2b491ba 100644
--- a/components/tracing/tracing_messages.h
+++ b/components/tracing/tracing_messages.h
@@ -16,10 +16,11 @@
 #define IPC_MESSAGE_START TracingMsgStart
 
 // Sent to all child processes to enable trace event recording.
-IPC_MESSAGE_CONTROL3(TracingMsg_BeginTracing,
+IPC_MESSAGE_CONTROL4(TracingMsg_BeginTracing,
                      std::string /*  category_filter_str */,
                      base::TimeTicks /* browser_time */,
-                     int /* base::debug::TraceLog::Options */)
+                     int /* base::debug::TraceLog::Options */,
+                     bool /* tracing_startup */)
 
 // Sent to all child processes to disable trace event recording.
 IPC_MESSAGE_CONTROL0(TracingMsg_EndTracing)