Introduce PositionInComposedTree version of enclosingBlock()

This patch introduces |PositionInComposedTree| version of |enclosingBlock()|
by introducing template function |enclosingBlockAlgorithm()|.

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=EditingUtilitiesTest.enclosingBlock

Review URL: https://codereview.chromium.org/1310073006

git-svn-id: svn://svn.chromium.org/blink/trunk@201303 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -648,12 +648,23 @@ Element* enclosingBlock(Node* node, EditingBoundaryCrossingRule rule)
     return enclosingBlock(firstPositionInOrBeforeNode(node), rule);
 }
 
-Element* enclosingBlock(const Position& position, EditingBoundaryCrossingRule rule)
+template <typename Strategy>
+Element* enclosingBlockAlgorithm(const PositionAlgorithm<Strategy>& position, EditingBoundaryCrossingRule rule)
 {
     Node* enclosingNode = enclosingNodeOfType(position, isEnclosingBlock, rule);
     return enclosingNode && enclosingNode->isElementNode() ? toElement(enclosingNode) : nullptr;
 }
 
+Element* enclosingBlock(const Position& position, EditingBoundaryCrossingRule rule)
+{
+    return enclosingBlockAlgorithm<EditingStrategy>(position, rule);
+}
+
+Element* enclosingBlock(const PositionInComposedTree& position, EditingBoundaryCrossingRule rule)
+{
+    return enclosingBlockAlgorithm<EditingInComposedTreeStrategy>(position, rule);
+}
+
 Element* enclosingBlockFlowElement(Node& node)
 {
     if (isBlockFlowElement(node))

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

@@ -70,7 +70,8 @@ Node* highestEnclosingNodeOfType(const Position&, bool (*nodeIsOfType)(const Nod
 Node* highestNodeToRemoveInPruning(Node*, Node* excludeNode = nullptr);
 
 Element* enclosingBlock(Node*, EditingBoundaryCrossingRule = CannotCrossEditingBoundary);
-Element* enclosingBlock(const Position&, EditingBoundaryCrossingRule);
+CORE_EXPORT Element* enclosingBlock(const Position&, EditingBoundaryCrossingRule);
+CORE_EXPORT Element* enclosingBlock(const PositionInComposedTree&, EditingBoundaryCrossingRule);
 Element* enclosingBlockFlowElement(Node&); // Deprecated, use enclosingBlock instead.
 bool inSameContainingBlockFlowElement(Node*, Node*);
 Element* enclosingTableCell(const Position&);

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

@@ -31,6 +31,21 @@ TEST_F(EditingUtilitiesTest, firstEditablePositionAfterPositionInRoot)
     EXPECT_EQ(PositionInComposedTree::afterNode(host), firstEditablePositionAfterPositionInRoot(PositionInComposedTree(three, 0), host));
 }
 
+TEST_F(EditingUtilitiesTest, enclosingBlock)
+{
+    const char* bodyContent = "<p id='host'><b id='one'>11</b></p>";
+    const char* shadowContent = "<content select=#two></content><div id='three'><content select=#one></content></div>";
+    setBodyContent(bodyContent);
+    RefPtrWillBeRawPtr<ShadowRoot> shadowRoot = setShadowContent(shadowContent);
+    updateLayoutAndStyleForPainting();
+    Node* host = document().getElementById("host");
+    Node* one = document().getElementById("one");
+    Node* three = shadowRoot->getElementById("three");
+
+    EXPECT_EQ(host, enclosingBlock(Position(one, 0), CannotCrossEditingBoundary));
+    EXPECT_EQ(three, enclosingBlock(PositionInComposedTree(one, 0), CannotCrossEditingBoundary));
+}
+
 TEST_F(EditingUtilitiesTest, enclosingNodeOfType)
 {
     const char* bodyContent = "<p id='host'><b id='one'>11</b></p>";