Don't emptify event.path after dispatching an event.

BUG=402749

Review URL: https://codereview.chromium.org/473833002

git-svn-id: svn://svn.chromium.org/blink/trunk@180284 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/fast/dom/shadow/event-path-expected.txt

+Makes sure that event.path is empty before dispatching the event.
+length: 0
 #b, #a, [object HTMLBodyElement], [object HTMLHtmlElement], [object HTMLDocument], length: 5
 Makes sure that event.path returns static NodeList.
 #b, #a, [object HTMLBodyElement], [object HTMLHtmlElement], [object HTMLDocument], length: 5
+Makes sure that event.path isn't emptified after dispatching the event.
+#b, #a, [object HTMLBodyElement], [object HTMLHtmlElement], [object HTMLDocument], length: 5
 PASS successfullyParsed is true
 
 TEST COMPLETE

third_party/WebKit/LayoutTests/fast/dom/shadow/event-path.html

@@ -24,8 +24,12 @@ b.addEventListener('click', function(event) {
     debug(dumpNodeList(event.path));
 });
 var clickEvent = document.createEvent("MouseEvents");
+debug("Makes sure that event.path is empty before dispatching the event.");
+debug(dumpNodeList(clickEvent.path));
 clickEvent.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
 b.dispatchEvent(clickEvent);
+debug("Makes sure that event.path isn't emptified after dispatching the event.");
+debug(dumpNodeList(clickEvent.path));
 </script>
 </body>
 </html>

third_party/WebKit/Source/core/events/Event.cpp

@@ -224,7 +224,17 @@ EventPath& Event::ensureEventPath()
 
 PassRefPtrWillBeRawPtr<StaticNodeList> Event::path() const
 {
-    if (!m_currentTarget || !m_currentTarget->toNode())
+    if (!m_currentTarget) {
+        ASSERT(m_eventPhase == PhaseType::NONE);
+        if (!m_eventPath) {
+            // Before dispatching the event
+            return StaticNodeList::createEmpty();
+        }
+        ASSERT(!m_eventPath->isEmpty());
+        // After dispatching the event
+        return m_eventPath->last().treeScopeEventContext().ensureEventPath(*m_eventPath);
+    }
+    if (!m_currentTarget->toNode())
         return StaticNodeList::createEmpty();
     Node* node = m_currentTarget->toNode();
     // FIXME: Support SVG Elements.

third_party/WebKit/Source/core/events/EventPath.h

@@ -55,7 +55,7 @@ public:
 
     NodeEventContext& operator[](size_t index) { return m_nodeEventContexts[index]; }
     const NodeEventContext& operator[](size_t index) const { return m_nodeEventContexts[index]; }
-    const NodeEventContext& last() const { return m_nodeEventContexts[size() - 1]; }
+    NodeEventContext& last() { return m_nodeEventContexts[size() - 1]; }
 
     bool isEmpty() const { return m_nodeEventContexts.isEmpty(); }
     size_t size() const { return m_nodeEventContexts.size(); }