Rename m_run to m_textRun in Shaper

Rename m_run to m_textRun in Shaper

Rename the ambiguously named m_run field in Shaper and, by extension, in
the sub-classes SimpleShaper and HarfBuzzShaper to m_textRun as the term
run is very overloaded in the context of shaping. The name textRun makes
it clear that it refers to a TextRun and not a shaping run, harfbuzz run
or bidi run. This is a name only change and doesn't change any behavior.

R=szager@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196884

[eae, 2015-06-10 17:42:51]

eae@chromium.org changed reviewers:
+ szager@chromium.org

[szager1, 2015-06-10 17:49:19]

lgtm

[eae, 2015-06-10 17:50:22]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2015-06-10 17:50:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1173533004/1

[commit-bot: I haz the power, 2015-06-10 17:53:52]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196884