Implement unicode bidi P2 and P3 rules in BidiResolver

Source/core/rendering/RenderBlockLineLayout.cpp

Index: Source/core/rendering/RenderBlockLineLayout.cpp
diff --git a/Source/core/rendering/RenderBlockLineLayout.cpp b/Source/core/rendering/RenderBlockLineLayout.cpp
index acf41172647deff8aeea17f8b7c88903e8db00e4..0dbb213e2f4e9596eb35e83f5fdcbcad4c23c0b2 100644
--- a/Source/core/rendering/RenderBlockLineLayout.cpp
+++ b/Source/core/rendering/RenderBlockLineLayout.cpp
@@ -240,25 +240,9 @@ static TextDirection determinePlaintextDirectionality(RenderObject* root, Render
 {
     InlineIterator iter(root, firstRenderObjectForDirectionalityDetermination(root, current), pos);
     InlineBidiResolver observer;
-    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;
+    observer.setPositionIgnoringNestedIsolates(iter);
+    return observer.determineParagraphDirectionality();
 }
 
 static void checkMidpoints(LineMidpointState& lineMidpointState, InlineIterator& lBreak)