Improve robustness of RenderCombine emphasis mark replacement character

Improve robustness of RenderCombine emphasis mark replacement character

Emphasis marks on RenderCombine objects are drawn using a fake text run 
containing one replacement character which should match the horizontal, 
compressed digits in size. The object replacement character U+FFFC, 
which was used before, does not reliably fulfill this requirement, the 
ideographic space works better.

BUG=418026
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182756

[Dominik Röttsches, 2014-09-26 10:54:18]

dominik.rottsches@intel.com changed reviewers:
+ behdad@chromium.org, eae@chromium.org

[eae, 2014-09-26 11:09:13]

Awsome, LGTM

[eae, 2014-09-26 11:09:18]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2014-09-26 11:10:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/605953002/20001

[behdad_google, 2014-09-26 11:41:31]

behdad@google.com changed reviewers:
+ behdad@google.com

[behdad_google, 2014-09-26 11:41:32]

lgtm

[behdad_google, 2014-09-26 11:44:03]

lgtm

I like this!

[commit-bot: I haz the power, 2014-09-26 12:15:11]

Committed patchset #2 (id:20001) as 182756