Introduce composed tree version of absoluteCaretBoundsOf()

This patch introduces composed tree version of |absoluteCaretBoundsOf()|
by templatizing original |absoluteCaretBoundsOf()| to work both DOM tree
position and composed tree position version 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/1330743002

git-svn-id: svn://svn.chromium.org/blink/trunk@201865 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -2500,7 +2500,8 @@ bool isVisuallyEquivalentCandidate(const PositionInComposedTree& position)
     return isVisuallyEquivalentCandidateAlgorithm<EditingInComposedTreeStrategy>(position);
 }
 
-IntRect absoluteCaretBoundsOf(const VisiblePosition& visiblePosition)
+template <typename Strategy>
+static IntRect absoluteCaretBoundsOfAlgorithm(const VisiblePositionTemplate<Strategy>& visiblePosition)
 {
     LayoutObject* layoutObject;
     LayoutRect localRect = localCaretRectOfPosition(visiblePosition.toPositionWithAffinity(), layoutObject);
@@ -2510,6 +2511,16 @@ IntRect absoluteCaretBoundsOf(const VisiblePosition& visiblePosition)
     return layoutObject->localToAbsoluteQuad(FloatRect(localRect)).enclosingBoundingBox();
 }
 
+IntRect absoluteCaretBoundsOf(const VisiblePosition& visiblePosition)
+{
+    return absoluteCaretBoundsOfAlgorithm<EditingStrategy>(visiblePosition);
+}
+
+IntRect absoluteCaretBoundsOf(const VisiblePositionInComposedTree& visiblePosition)
+{
+    return absoluteCaretBoundsOfAlgorithm<EditingInComposedTreeStrategy>(visiblePosition);
+}
+
 static VisiblePosition skipToEndOfEditingBoundary(const VisiblePosition& pos, const Position& anchor)
 {
     if (pos.isNull())

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

@@ -90,6 +90,7 @@ CORE_EXPORT PositionInComposedTree canonicalPositionOf(const PositionInComposedT
 
 // Bounds of (possibly transformed) caret in absolute coords
 CORE_EXPORT IntRect absoluteCaretBoundsOf(const VisiblePosition&);
+CORE_EXPORT IntRect absoluteCaretBoundsOf(const VisiblePositionInComposedTree&);
 
 UChar32 characterAfter(const VisiblePosition&);
 UChar32 characterBefore(const VisiblePosition&);

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

@@ -27,6 +27,24 @@ PositionInComposedTreeWithAffinity positionWithAffinityInComposedTree(Node& anch
 class VisibleUnitsTest : public EditingTestBase {
 };
 
+TEST_F(VisibleUnitsTest, absoluteCaretBoundsOf)
+{
+    const char* bodyContent = "<p id='host'><b id='one'>11</b><b id='two'>22</b></p>";
+    const char* shadowContent = "<div><content select=#two></content><content select=#one></content></div>";
+    setBodyContent(bodyContent);
+    RefPtrWillBeRawPtr<ShadowRoot> shadowRoot = setShadowContent(shadowContent, "host");
+    updateLayoutAndStyleForPainting();
+
+    RefPtrWillBeRawPtr<Element> body = document().body();
+    RefPtrWillBeRawPtr<Element> one = body->querySelector("#one", ASSERT_NO_EXCEPTION);
+
+    IntRect boundsInDOMTree = absoluteCaretBoundsOf(createVisiblePosition(Position(one.get(), 0)));
+    IntRect boundsInComposedTree = absoluteCaretBoundsOf(createVisiblePosition(PositionInComposedTree(one.get(), 0)));
+
+    EXPECT_FALSE(boundsInDOMTree.isEmpty());
+    EXPECT_EQ(boundsInDOMTree, boundsInComposedTree);
+}
+
 TEST_F(VisibleUnitsTest, inSameLine)
 {
     const char* bodyContent = "<p id='host'>00<b id='one'>11</b><b id='two'>22</b>33</p>";