Revert of Add tab support to RenderBlockLineLayout::stripTrailingSpace

Revert of Add tab support to RenderBlockLineLayout::stripTrailingSpace (patchset #1 id:1 of https://codereview.chromium.org/836863002/)

Reason for revert:
trailing_whitespace_wrapping.html is crashing on Mac10.6 (dbg)

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=fast%2Ftext%2Ftrailing_whitespace_wrapping.html%2Cvirtual%2Fantialiasedtext%2Ffast%2Ftext%2Ftrailing_whitespace_wrapping.html%2Cvirtual%2Fslimmingpaint%2Ffast%2Ftext%2Ftrailing_whitespace_wrapping.html

Example:
22:23:47.008 3912 worker/4 fast/text/trailing_whitespace_wrapping.html crashed, (stderr lines):
22:23:47.008 3912   Assertion failed: (bool (status_and & kCTRunStatusRightToLeft) == backward), function _hb_coretext_shape, file ../../third_party/harfbuzz-ng/src/hb-coretext.cc, line 989.
22:23:47.009 3881 [30380/38782] fast/text/trailing_whitespace_wrapping.html failed unexpectedly (renderer crashed [pid=6953])

Original issue's description:
> Add tab support to RenderBlockLineLayout::stripTrailingSpace
> 
> Change RenderBlockLineLayout::stripTrailingSpace to measure the width of
> the first trailing white-space character instead of always assuming it's
> a space character. This fixes a bug where we wrap text unnecessarily for
> elements with a trailing tab character as we correctly measure the right
> character (tab) when computing the preferred with but subtract the width
> of a space character in stripTrailingSpace.
> 
> R=pdr@chromium.org
> BUG=444544
> TEST=fast/text/trailing_whitespace_wrapping.html
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=187878

TBR=pdr@chromium.org,eae@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=444544
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=187897

[falken, 2015-01-06 06:52:09]

Created Revert of Add tab support to RenderBlockLineLayout::stripTrailingSpace

[falken, 2015-01-06 06:58:28]

The CQ bit was checked by falken@chromium.org

[commit-bot: I haz the power, 2015-01-06 06:58:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/836103002/1

[commit-bot: I haz the power, 2015-01-06 06:59:25]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=187897