Make cygprofile use clock_gettime() instead of gettimeofday().

Make cygprofile use clock_gettime() instead of gettimeofday().                                                                                                                                                                                                                                                                 

Some of the generated orderfiles looked suspicious. I could observe that one of
them had the renderer PID show up before the browser one.

The mergetraces.py file was also occasionally complaining about unsorted
timestamps.

There are not many situations where gettimeofday() should be used instead of
clock_gettime(). The former is not monotonic in particular.
The original code also had the issue that it was using both gettimeofday() and 
time().

This also replaces the occurrences of 'ms(ec)' with 'us(ec)' to make it clear
that microseconds are used as opposed to milliseconds.

BUG=372323
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270090

[pasko, 2014-05-12 12:09:34]

non-owner lgtm! great catch!

https://codereview.chromium.org/272393004/diff/40001/tools/cygprofile/mergetr...
File tools/cygprofile/mergetraces.py (right):

https://codereview.chromium.org/272393004/diff/40001/tools/cygprofile/mergetr...
tools/cygprofile/mergetraces.py:88: raise Exception("WARNING: last_timestamp: "
+ str(last_timestamp_secs)
nit:

with an exception it is no longer a warning

[Philippe, 2014-05-13 09:48:10]

Thanks Egor!

Committer approval would actually be enough since there is no specific owner for
cygprofile nor for tools/.

https://chromiumcodereview.appspot.com/272393004/diff/40001/tools/cygprofile/...
File tools/cygprofile/mergetraces.py (right):

https://chromiumcodereview.appspot.com/272393004/diff/40001/tools/cygprofile/...
tools/cygprofile/mergetraces.py:88: raise Exception("WARNING: last_timestamp: "
+ str(last_timestamp_secs)
On 2014/05/12 12:09:34, pasko wrote:
> nit:
> 
> with an exception it is no longer a warning

Yeah :)

[Philippe, 2014-05-13 09:48:34]

The CQ bit was checked by pliard@chromium.org

[commit-bot: I haz the power, 2014-05-13 09:48:56]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/pliard@chromium.org/272393004/60001

[commit-bot: I haz the power, 2014-05-13 11:11:46]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/18...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[commit-bot: I haz the power, 2014-05-13 11:41:35]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-05-13 11:41:35]

Try jobs failed on following builders:
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/18...)

[Philippe, 2014-05-13 12:46:26]

The CQ bit was checked by pliard@chromium.org

[commit-bot: I haz the power, 2014-05-13 12:46:32]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/pliard@chromium.org/272393004/60001

[commit-bot: I haz the power, 2014-05-13 14:06:11]

Change committed as 270090