Add ASYNC_STEP support to trace_event and change START to ASYNC_BEGIN.

Add ASYNC_STEP support to trace_event and change START to ASYNC_BEGIN.

BUG=116095
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=124348

[jbates, 2012-02-28 22:46:21]

nduca: please review
jar: base/ OWNERS

[nduca, 2012-02-28 23:55:25]

Mind updating the json example in the chrome/browser/resources/tracing/data
folder too?

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event.h
File base/debug/trace_event.h (right):

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event....
base/debug/trace_event.h:386: // - |id| is used to match the ASYNC_BEGIN event
with the ASYNC_END event. It
should we clarify that we match on name AND id? e.g. this is seen as a single
async operation:
  async_begin("cat", "x", 7);
  async_step("cat", "x", 7);
  async_end("cat", "x", 7);
but this isn't:
  async_begin("cat", "x", 7);
  async_step("cat", "y", 7); // will not connect to x or z
  async_end("cat", "z", 7); // will not connect to x and y

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event_...
File base/debug/trace_event_unittest.cc (left):

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event_...
base/debug/trace_event_unittest.cc:327: TRACE_EVENT_START1("all",
"TRACE_EVENT_START1 call", 5,
tests for the step?

[nduca, 2012-02-28 23:55:32]

LGTM with above nits

[jbates, 2012-02-29 00:34:19]

>Mind updating the json example in the chrome/browser/resources/tracing/data
folder too?

Done.

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event.h
File base/debug/trace_event.h (right):

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event....
base/debug/trace_event.h:386: // - |id| is used to match the ASYNC_BEGIN event
with the ASYNC_END event. It
On 2012/02/28 23:55:26, nduca wrote:
> should we clarify that we match on name AND id? e.g. this is seen as a single
> async operation:
>   async_begin("cat", "x", 7);
>   async_step("cat", "x", 7);
>   async_end("cat", "x", 7);
> but this isn't:
>   async_begin("cat", "x", 7);
>   async_step("cat", "y", 7); // will not connect to x or z
>   async_end("cat", "z", 7); // will not connect to x and y

Done.

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event_...
File base/debug/trace_event_unittest.cc (left):

https://chromiumcodereview.appspot.com/9522010/diff/1/base/debug/trace_event_...
base/debug/trace_event_unittest.cc:327: TRACE_EVENT_START1("all",
"TRACE_EVENT_START1 call", 5,
On 2012/02/28 23:55:26, nduca wrote:
> tests for the step?

Done.

[jar (doing other things), 2012-02-29 23:32:25]

Rubber stamp LGTM

[commit-bot: I haz the power, 2012-02-29 23:34:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jbates@chromium.org/9522010/7

[commit-bot: I haz the power, 2012-03-01 03:05:02]

Change committed as 124348