style: Rename the PseudoId enum values to CamelCase and prefix them.

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

Index: third_party/WebKit/Source/core/events/EventPathTest.cpp
diff --git a/third_party/WebKit/Source/core/events/EventPathTest.cpp b/third_party/WebKit/Source/core/events/EventPathTest.cpp
index 4a1acbf35c01757ebc82d5eb8cf8ac3e77a19165..eb75b018ac548080fb3d05e1665c87e4b2e77fd1 100644
--- a/third_party/WebKit/Source/core/events/EventPathTest.cpp
+++ b/third_party/WebKit/Source/core/events/EventPathTest.cpp
@@ -31,7 +31,7 @@ void EventPathTest::SetUp()
 TEST_F(EventPathTest, ShouldBeEmptyForPseudoElementWithoutParentElement)
 {
     RefPtrWillBeRawPtr<Element> div = document().createElement(HTMLNames::divTag, false);
-    RefPtrWillBeRawPtr<PseudoElement> pseudo = PseudoElement::create(div.get(), FIRST_LETTER);
+    RefPtrWillBeRawPtr<PseudoElement> pseudo = PseudoElement::create(div.get(), PseudoIdFirstLetter);
     pseudo->dispose();
     EventPath eventPath(*pseudo);
     EXPECT_TRUE(eventPath.isEmpty());