Fix perf profiler incorrect library collection in some cases.

Fix perf profiler incorrect library collection in some cases.

Some devices report a mysterious "[vectors]" library necessary to
symbolize a given perf profile. This change makes the script ignore it.

BUG=422291
Committed: https://crrev.com/332b63b253857e58a48e92cb00a6cc22239f5d47
Cr-Commit-Position: refs/heads/master@{#302836}

[Fabrice (no longer in Chrome), 2014-10-22 14:31:59]

fdegans@chromium.org changed reviewers:
+ tonyg@chromium.org

[Fabrice (no longer in Chrome), 2014-10-22 14:31:59]

PTAL

[tonyg, 2014-10-22 19:44:32]

tonyg@chromium.org changed reviewers:
+ skyostil@google.com

[tonyg, 2014-10-22 19:44:59]

lgtm

The style guide prefers "not path" instead of "path == ''"

[Sami, 2014-10-23 11:20:47]

skyostil@chromium.org changed reviewers:
+ skyostil@chromium.org

[Sami, 2014-10-23 11:20:48]

Would you mind adding a [vectors] line into sample_perf_report_output.txt too?

[Fabrice (no longer in Chrome), 2014-11-05 16:53:48]

On 2014/10/23 11:20:48, Sami wrote:
> Would you mind adding a [vectors] line into sample_perf_report_output.txt too?

Sorry that took so long, here you go!

[tonyg, 2014-11-05 16:54:52]

The CQ bit was checked by tonyg@chromium.org

[tonyg, 2014-11-05 16:54:53]

lgtm

[commit-bot: I haz the power, 2014-11-05 16:55:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/669163002/20001

[commit-bot: I haz the power, 2014-11-05 18:46:56]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-11-05 18:47:39]

Patchset 2 (id:??) landed as
https://crrev.com/332b63b253857e58a48e92cb00a6cc22239f5d47
Cr-Commit-Position: refs/heads/master@{#302836}