Implement unicode bidi P2 and P3 rules in BidiResolver

Source/core/rendering/RenderBlockLineLayout.cpp

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 222 matching lines @@
         current = next;
     }
 
     return current;
 }
 
 static TextDirection determinePlaintextDirectionality(RenderObject* root, RenderObject* current = 0, unsigned pos = 0)
 {
     InlineIterator iter(root, firstRenderObjectForDirectionalityDetermination(root, current), pos);
     InlineBidiResolver observer;
+    observer.setStatus(BidiStatus(root->style()->direction(), isOverride(root->style()->unicodeBidi())));
     observer.setPositionIgnoringNestedIsolates(iter);
-    observer.setStatus(BidiStatus(root->style()->direction(), isOverride(root->style()->unicodeBidi())));
-    while (!iter.atEnd()) {
-        if (observer.inIsolate()) {
-            iter.increment(&observer, InlineIterator::FastIncrementInIsolatedRenderer);
-            continue;
-        }
-        if (iter.atParagraphSeparator())
-            break;
-        if (UChar current = iter.current()) {
-            Direction charDirection = direction(current);
-            if (charDirection == LeftToRight)
-                return LTR;
-            if (charDirection == RightToLeft || charDirection == RightToLeftArabic)
-                return RTL;
-        }
-        iter.increment(&observer);
-    }
-    return LTR;
+    return observer.determineParagraphDirectionality();
 }
 
 static void checkMidpoints(LineMidpointState& lineMidpointState, InlineIterator& lBreak)
 {
     // Check to see if our last midpoint is a start point beyond the line break.  If so,
     // shave it off the list, and shave off a trailing space if the previous end point doesn't
     // preserve whitespace.
     if (lBreak.m_obj && lineMidpointState.numMidpoints && !(lineMidpointState.numMidpoints % 2)) {
         InlineIterator* midpoints = lineMidpointState.midpoints.data();
         InlineIterator& endpoint = midpoints[lineMidpointState.numMidpoints - 2];
@@ skipping 3103 matching lines @@
     lineGridBox->alignBoxesInBlockDirection(logicalHeight(), textBoxDataMap, verticalPositionCache);
 
     setLineGridBox(lineGridBox);
 
     // FIXME: If any of the characteristics of the box change compared to the old one, then we need to do a deep dirtying
     // (similar to what happens when the page height changes). Ideally, though, we only do this if someone is actually snapping
     // to this grid.
 }
 
 }