TextAutosizer: avoid unnecessary calls to containerShouldBeAutosized.

TextAutosizer: avoid unnecessary calls to containerShouldBeAutosized.

This patch adds a simple check to ensure that the multiplier > 1
before calling containerShouldBeAutosized() inside processContainer().
If the multiplier is exactly 1 the return value of
containerShouldBeAutosized does not matter. Due to the cascading
structure of the algorithm quite a few unnecessary calls to
containerShouldBeAutosized are avoided in this way, reducing the text
autosizing times by up to 30% on some websites.

Reduction of measured time spent in text autosizing (in %):
amazon.co.uk - 17%
www.nytimes.com - 27%
www.answers.com - 31%
www.yahoo.com - 16%
http://en.wikipedia.org/wiki/Cat - 9%

BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=165479

[timvolodine, 2014-01-21 19:37:46]

for more timings:
https://docs.google.com/a/google.com/spreadsheets/d/1H_ilEGa4SjFsuWv9Hu0W6Qxg...

[pdr., 2014-01-21 19:39:10]

On 2014/01/21 19:37:46, timvolodine wrote:
> for more timings:
>
https://docs.google.com/a/google.com/spreadsheets/d/1H_ilEGa4SjFsuWv9Hu0W6Qxg...

LGTM

[commit-bot: I haz the power, 2014-01-21 19:40:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/timvolodine@chromium.org/134153006/1

[commit-bot: I haz the power, 2014-01-21 20:49:59]

Change committed as 165479

[pdr., 2014-01-21 21:15:15]

On 2014/01/21 20:49:59, I haz the power (commit-bot) wrote:
> Change committed as 165479

Lets keep an eye on
https://chromeperf.appspot.com/report?masters=ChromiumPerf&bots=android-nexus...

If this doesn't show a perf win, we need to fix our tests :)