Introduce composed tree version of localCaretRectOfPosition()

This patch introduces composed tree version of |localCaretRectOfPosition()|
by templatizing function to share algorithm.

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

BUG=513568
TEST=webkit_unit_tests --gtest_filter=VisibleUnitsTest.localCaretRectOfPosition

Review URL: https://codereview.chromium.org/1317503002

git-svn-id: svn://svn.chromium.org/blink/trunk@201124 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -1713,7 +1713,8 @@ InlineBoxPosition computeInlineBoxPosition(const PositionInComposedTree& positio
     return computeInlineBoxPositionAlgorithm<EditingInComposedTreeStrategy>(position, affinity, primaryDirection);
 }
 
-LayoutRect localCaretRectOfPosition(const PositionWithAffinity& position, LayoutObject*& layoutObject)
+template <typename Strategy>
+LayoutRect localCaretRectOfPositionAlgorithm(const PositionWithAffinityTemplate<Strategy>& position, LayoutObject*& layoutObject)
 {
     if (position.position().isNull()) {
         layoutObject = nullptr;
@@ -1733,6 +1734,16 @@ LayoutRect localCaretRectOfPosition(const PositionWithAffinity& position, Layout
     return layoutObject->localCaretRect(boxPosition.inlineBox, boxPosition.offsetInBox);
 }
 
+LayoutRect localCaretRectOfPosition(const PositionWithAffinity& position, LayoutObject*& layoutObject)
+{
+    return localCaretRectOfPositionAlgorithm<EditingStrategy>(position, layoutObject);
+}
+
+LayoutRect localCaretRectOfPosition(const PositionInComposedTreeWithAffinity& position, LayoutObject*& layoutObject)
+{
+    return localCaretRectOfPositionAlgorithm<EditingInComposedTreeStrategy>(position, layoutObject);
+}
+
 static int boundingBoxLogicalHeight(LayoutObject *o, const IntRect &rect)
 {
     return o->style()->isHorizontalWritingMode() ? rect.height() : rect.width();

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

@@ -152,7 +152,8 @@ CORE_EXPORT InlineBoxPosition computeInlineBoxPosition(const PositionInComposedT
 CORE_EXPORT InlineBoxPosition computeInlineBoxPosition(const VisiblePosition&);
 
 // Rect is local to the returned layoutObject
-LayoutRect localCaretRectOfPosition(const PositionWithAffinity&, LayoutObject*&);
+CORE_EXPORT LayoutRect localCaretRectOfPosition(const PositionWithAffinity&, LayoutObject*&);
+CORE_EXPORT LayoutRect localCaretRectOfPosition(const PositionInComposedTreeWithAffinity&, LayoutObject*&);
 bool hasRenderedNonAnonymousDescendantsWithHeight(LayoutObject*);
 
 // Returns a hit-tested VisiblePosition for the given point in contents-space

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

@@ -52,6 +52,26 @@ TEST_F(VisibleUnitsTest, inSameLine)
     EXPECT_TRUE(inSameLine(positionWithAffinityInComposedTree(*two->firstChild(), 0), positionWithAffinityInComposedTree(*four->firstChild(), 0)));
 }
 
+TEST_F(VisibleUnitsTest, localCaretRectOfPosition)
+{
+    const char* bodyContent = "<p id='host'><b id='one'>1</b></p><b id='two'>22</b>";
+    const char* shadowContent = "<b id='two'>22</b><content select=#one></content><b id='three'>333</b>";
+    setBodyContent(bodyContent);
+    setShadowContent(shadowContent);
+    updateLayoutAndStyleForPainting();
+
+    RefPtrWillBeRawPtr<Element> one = document().getElementById("one");
+
+    LayoutObject* layoutObjectFromDOMTree;
+    LayoutRect layoutRectFromDOMTree = localCaretRectOfPosition(Position(one, 0), layoutObjectFromDOMTree);
+
+    LayoutObject* layoutObjectFromComposedTree;
+    LayoutRect layoutRectFromComposedTree = localCaretRectOfPosition(PositionInComposedTree(one, 0), layoutObjectFromComposedTree);
+
+    EXPECT_EQ(layoutObjectFromDOMTree, layoutObjectFromComposedTree);
+    EXPECT_EQ(layoutRectFromDOMTree, layoutRectFromComposedTree);
+}
+
 TEST_F(VisibleUnitsTest, mostBackwardCaretPositionAfterAnchor)
 {
     const char* bodyContent = "<p id='host'><b id='one'>1</b></p><b id='two'>22</b>";