Improve usages of trace_event locks

Improve usages of trace_event locks

1. Move category_group_enabled checking out of lock.
2. Move thread_name checking out of lock. Lock on thread_name changes
to check and update thread_names_ map.
3. Check if thread_id is the id of the current thread before checking
thread name change.
4. Move TraceEvent construction out of lock.
5. Put code ECHO_TO_CONSOLE code together and under lock.
6. Add a missing lock in TraceLog::RemoveProcessLabel().

This is the first step for bug 264667. Next step is thread-local event
buffer.

BUG=264667
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=216791

[dsinclair, 2013-08-09 18:29:23]

+nduca

[dsinclair, 2013-08-09 18:35:58]

This lgtm, but would like to get nduca to take a look at it first.

[nduca, 2013-08-09 19:17:57]

lgtm though i didn't give it a careful check. lets learn by trying :)

[Xianzhu, 2013-08-09 19:34:28]

There seems some problem of Patch Set 2, which will return early when the buffer
is full without calling event_callback_. The original code will call
event_callback_ even if the buffer is full. So I'd like to abandon Patch Set 2
and submit Patch Set 1. Does this look good?

[dsinclair, 2013-08-09 19:51:43]

On 2013/08/09 19:34:28, Xianzhu wrote:
> There seems some problem of Patch Set 2, which will return early when the
buffer
> is full without calling event_callback_. The original code will call
> event_callback_ even if the buffer is full. So I'd like to abandon Patch Set 2
> and submit Patch Set 1. Does this look good?

sgtm, I'd originally reviewed patchset 1.

[commit-bot: I haz the power, 2013-08-09 20:26:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/22294006/1

[commit-bot: I haz the power, 2013-08-10 00:48:10]

Change committed as 216791