Fix alignment for bidirectional text.

In the css3-text spec:

The start and end edges of a line box are determined by the inline base
direction of the line box. In most cases, this is given by its
containing block's computed ‘direction’. However if its containing block
has ‘unicode-bidi: plaintext’, the inline base direction the line box must
be determined by the base direction of the bidi paragraph to which it
belongs: that is, the bidi paragraph for which the line box holds content.

This patch just implements the behavior described above modifying
updateLogicalWidthForAlignment and setting the bidi level of the
RootInlineBox.

Additionally, modify two layout tests to make it conforming to the spec.

BUG=280709
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=157263

[eseidel, 2013-09-03 18:30:09]

This looks reasonable.  Levi?

[leviw_travelin_and_unemployed, 2013-09-03 20:00:26]

The code change looks fine, and matching Firefox is a plus, but since this
behavior isn't explicitly specced out I asked Aharon on the bug to see if he has
anything to contribute since his last comments. LGTM if there aren't any
objections.

[commit-bot: I haz the power, 2013-09-04 20:22:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/igor.o@sisa.samsung.com/23567004/1

[commit-bot: I haz the power, 2013-09-04 21:45:38]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/igor.o@sisa.samsung.com/23567004/1

[commit-bot: I haz the power, 2013-09-04 23:05:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/igor.o@sisa.samsung.com/23567004/19001

[commit-bot: I haz the power, 2013-09-04 23:06:02]

Failed to apply patch for LayoutTests/TestExpectations:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file LayoutTests/TestExpectations
  Hunk #1 FAILED at 1286.
  1 out of 1 hunk FAILED -- saving rejects to file
LayoutTests/TestExpectations.rej

Patch:       LayoutTests/TestExpectations
Index: LayoutTests/TestExpectations
diff --git a/LayoutTests/TestExpectations b/LayoutTests/TestExpectations
index
cb0b4f74f53385e30db09dcbf3173544b46d3c77..dc980356e36c6c8cb5baa8f7762e4d031cc9a0e5
100644
--- a/LayoutTests/TestExpectations
+++ b/LayoutTests/TestExpectations
@@ -1286,3 +1286,6 @@ crbug.com/282634 [ SnowLeopard Debug ]
svg/as-object/nested-embedded-svg-size-ch
 crbug.com/284779 crbug.com/284782
http/tests/media/media-source/mediasource-duration.html [ Failure Pass Crash ]
 crbug.com/284789 http/tests/media/media-source/mediasource-buffered.html [
Failure Pass ]
 crbug.com/284793
http/tests/media/media-source/mediasource-play-then-seek-back.html [ Failure
Pass ]
+
+crbug.com/280709
fast/text/international/unicode-bidi-plaintext-in-textarea.html [
NeedsRebaseline ]
+crbug.com/280709 fast/text/international/unicode-bidi-plaintext.html [
NeedsRebaseline ]

[commit-bot: I haz the power, 2013-09-04 23:20:06]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/igor.o@sisa.samsung.com/23567004/25001

[commit-bot: I haz the power, 2013-09-05 02:27:08]

Change committed as 157263