Introduce composed tree version of inSameLine()

This patch introduces composed tree version of |inSameLine()| for introducing
composed tree version of |VisibleSelection| class.

This patch is a preparation of making selection to handle granularity for web
component, http://crrev.com/1277863002

BUG=513568
TEST=n/a; no behavior changes

Review URL: https://codereview.chromium.org/1310913004

git-svn-id: svn://svn.chromium.org/blink/trunk@201868 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/editing/VisibleUnits.cpp

@@ -1121,6 +1121,11 @@ bool inSameLine(const VisiblePosition& position1, const VisiblePosition& positio
     return inSameLine(position1.toPositionWithAffinity(), position2.toPositionWithAffinity());
 }
 
+bool inSameLine(const VisiblePositionInComposedTree& position1, const VisiblePositionInComposedTree& position2)
+{
+    return inSameLine(position1.toPositionWithAffinity(), position2.toPositionWithAffinity());
+}
+
 bool isStartOfLine(const VisiblePosition& p)
 {
     return p.isNotNull() && p.deepEquivalent() == startOfLine(p).deepEquivalent();

third_party/WebKit/Source/core/editing/VisibleUnits.h

@@ -121,6 +121,7 @@ VisiblePosition endOfLine(const VisiblePosition&);
 CORE_EXPORT VisiblePosition previousLinePosition(const VisiblePosition&, LayoutUnit lineDirectionPoint, EditableType = ContentIsEditable);
 CORE_EXPORT VisiblePosition nextLinePosition(const VisiblePosition&, LayoutUnit lineDirectionPoint, EditableType = ContentIsEditable);
 CORE_EXPORT bool inSameLine(const VisiblePosition&, const VisiblePosition&);
+CORE_EXPORT bool inSameLine(const VisiblePositionInComposedTree&, const VisiblePositionInComposedTree&);
 CORE_EXPORT bool inSameLine(const PositionWithAffinity&, const PositionWithAffinity&);
 CORE_EXPORT bool inSameLine(const PositionInComposedTreeWithAffinity&, const PositionInComposedTreeWithAffinity&);
 bool isStartOfLine(const VisiblePosition&);

third_party/WebKit/Source/core/editing/VisibleUnitsTest.cpp

@@ -17,11 +17,21 @@ PositionWithAffinity positionWithAffinityInDOMTree(Node& anchor, int offset, Tex
     return PositionWithAffinity(canonicalPositionOf(Position(&anchor, offset)), affinity);
 }
 
+VisiblePosition createVisiblePositionInDOMTree(Node& anchor, int offset, TextAffinity affinity = TextAffinity::Downstream)
+{
+    return createVisiblePosition(Position(&anchor, offset), affinity);
+}
+
 PositionInComposedTreeWithAffinity positionWithAffinityInComposedTree(Node& anchor, int offset, TextAffinity affinity = TextAffinity::Downstream)
 {
     return PositionInComposedTreeWithAffinity(canonicalPositionOf(PositionInComposedTree(&anchor, offset)), affinity);
 }
 
+VisiblePositionInComposedTree createVisiblePositionInComposedTree(Node& anchor, int offset, TextAffinity affinity = TextAffinity::Downstream)
+{
+    return createVisiblePosition(PositionInComposedTree(&anchor, offset), affinity);
+}
+
 } // namespace
 
 class VisibleUnitsTest : public EditingTestBase {
@@ -64,10 +74,20 @@ TEST_F(VisibleUnitsTest, inSameLine)
     EXPECT_FALSE(inSameLine(positionWithAffinityInDOMTree(*one->firstChild(), 0), positionWithAffinityInDOMTree(*five->firstChild(), 0)));
     EXPECT_FALSE(inSameLine(positionWithAffinityInDOMTree(*two->firstChild(), 0), positionWithAffinityInDOMTree(*four->firstChild(), 0)));
 
+    EXPECT_TRUE(inSameLine(createVisiblePositionInDOMTree(*one, 0), createVisiblePositionInDOMTree(*two, 0)));
+    EXPECT_TRUE(inSameLine(createVisiblePositionInDOMTree(*one->firstChild(), 0), createVisiblePositionInDOMTree(*two->firstChild(), 0)));
+    EXPECT_FALSE(inSameLine(createVisiblePositionInDOMTree(*one->firstChild(), 0), createVisiblePositionInDOMTree(*five->firstChild(), 0)));
+    EXPECT_FALSE(inSameLine(createVisiblePositionInDOMTree(*two->firstChild(), 0), createVisiblePositionInDOMTree(*four->firstChild(), 0)));
+
     EXPECT_FALSE(inSameLine(positionWithAffinityInComposedTree(*one, 0), positionWithAffinityInComposedTree(*two, 0)));
     EXPECT_FALSE(inSameLine(positionWithAffinityInComposedTree(*one->firstChild(), 0), positionWithAffinityInComposedTree(*two->firstChild(), 0)));
     EXPECT_FALSE(inSameLine(positionWithAffinityInComposedTree(*one->firstChild(), 0), positionWithAffinityInComposedTree(*five->firstChild(), 0)));
     EXPECT_TRUE(inSameLine(positionWithAffinityInComposedTree(*two->firstChild(), 0), positionWithAffinityInComposedTree(*four->firstChild(), 0)));
+
+    EXPECT_FALSE(inSameLine(createVisiblePositionInComposedTree(*one, 0), createVisiblePositionInComposedTree(*two, 0)));
+    EXPECT_FALSE(inSameLine(createVisiblePositionInComposedTree(*one->firstChild(), 0), createVisiblePositionInComposedTree(*two->firstChild(), 0)));
+    EXPECT_FALSE(inSameLine(createVisiblePositionInComposedTree(*one->firstChild(), 0), createVisiblePositionInComposedTree(*five->firstChild(), 0)));
+    EXPECT_TRUE(inSameLine(createVisiblePositionInComposedTree(*two->firstChild(), 0), createVisiblePositionInComposedTree(*four->firstChild(), 0)));
 }
 
 TEST_F(VisibleUnitsTest, localCaretRectOfPosition)