Avoid style clobbering in setCompositionFromExistingText. (2nd land)

Source/core/paint/InlineTextBoxPainter.cpp

Index: Source/core/paint/InlineTextBoxPainter.cpp
diff --git a/Source/core/paint/InlineTextBoxPainter.cpp b/Source/core/paint/InlineTextBoxPainter.cpp
index eccefdcefdec29dc46ad70ed2bf67e374c7e8197..f7fb0127994de4f2793c770951120572e0758604 100644
--- a/Source/core/paint/InlineTextBoxPainter.cpp
+++ b/Source/core/paint/InlineTextBoxPainter.cpp
@@ -79,8 +79,8 @@ void InlineTextBoxPainter::paint(const PaintInfo& paintInfo, const LayoutPoint&
     }
 
     // Determine whether or not we have composition underlines to draw.
-    bool containsComposition = m_inlineTextBox.layoutObject().node() && m_inlineTextBox.layoutObject().frame()->inputMethodController().compositionNode() == m_inlineTextBox.layoutObject().node();
-    bool useCustomUnderlines = containsComposition && m_inlineTextBox.layoutObject().frame()->inputMethodController().compositionUsesCustomUnderlines();
+    bool containsComposition = m_inlineTextBox.layoutObject().node() && m_inlineTextBox.layoutObject().frame()->inputMethodController().isCompositionNode(m_inlineTextBox.layoutObject().node());

[yosin_UTC9, 2015/08/31 01:35:40]

Note: |isCompositionNode(Node*)| should be fast, since it is called for every
|Text| nodes.

+    bool useCustomUnderlines = containsComposition && m_inlineTextBox.layoutObject().frame()->inputMethodController().customCompositionUnderlines(m_inlineTextBox.layoutObject().node());
 
     // The text clip phase already has a DrawingRecorder. Text clips are initiated only in BoxPainter::paintLayerExtended, which is already
     // within a DrawingRecorder.
@@ -247,12 +247,13 @@ void InlineTextBoxPainter::paint(const PaintInfo& paintInfo, const LayoutPoint&
 
         // Paint custom underlines for compositions.
         if (useCustomUnderlines) {
-            const Vector<CompositionUnderline>& underlines = m_inlineTextBox.layoutObject().frame()->inputMethodController().customCompositionUnderlines();
-            CompositionUnderlineRangeFilter filter(underlines, m_inlineTextBox.start(), m_inlineTextBox.end());
-            for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
-                if (it->color == Color::transparent)
-                    continue;
-                paintCompositionUnderline(context, boxOrigin, *it);
+            if (const Vector<CompositionUnderline>* underlines = m_inlineTextBox.layoutObject().frame()->inputMethodController().customCompositionUnderlines(m_inlineTextBox.layoutObject().node())) {
+                CompositionUnderlineRangeFilter filter(*underlines, m_inlineTextBox.start(), m_inlineTextBox.end());
+                for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
+                    if (it->color == Color::transparent)
+                        continue;
+                    paintCompositionUnderline(context, boxOrigin, *it);
+                }
             }
         }
     }
@@ -278,14 +279,14 @@ void InlineTextBoxPainter::paintCompositionBackgrounds(GraphicsContext* pt, cons
 {
     if (useCustomUnderlines) {
         // Paint custom background highlights for compositions.
-        const Vector<CompositionUnderline>& underlines = m_inlineTextBox.layoutObject().frame()->inputMethodController().customCompositionUnderlines();
-        CompositionUnderlineRangeFilter filter(underlines, m_inlineTextBox.start(), m_inlineTextBox.end());
-        for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
-            if (it->backgroundColor == Color::transparent)
-                continue;
-            paintSingleCompositionBackgroundRun(pt, boxOrigin, style, font, it->backgroundColor, underlinePaintStart(*it), underlinePaintEnd(*it));
+        if (const Vector<CompositionUnderline>* underlines = m_inlineTextBox.layoutObject().frame()->inputMethodController().customCompositionUnderlines(m_inlineTextBox.layoutObject().node())) {
+            CompositionUnderlineRangeFilter filter(*underlines, m_inlineTextBox.start(), m_inlineTextBox.end());
+            for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
+                if (it->backgroundColor == Color::transparent)
+                    continue;
+                paintSingleCompositionBackgroundRun(pt, boxOrigin, style, font, it->backgroundColor, underlinePaintStart(*it), underlinePaintEnd(*it));
+            }
         }
-
     } else {
         paintSingleCompositionBackgroundRun(pt, boxOrigin, style, font, LayoutTheme::theme().platformDefaultCompositionBackgroundColor(),
             m_inlineTextBox.layoutObject().frame()->inputMethodController().compositionStart(),