Rename 'UseCounter::observe' to 'UseCounter::count'.

Source/core/dom/EventTarget.cpp

Index: Source/core/dom/EventTarget.cpp
diff --git a/Source/core/dom/EventTarget.cpp b/Source/core/dom/EventTarget.cpp
index c8c2d40299daecf876276a48d2d168c69799a6ee..8190effd275771b5631701407e1d8f5dfcc34181 100644
--- a/Source/core/dom/EventTarget.cpp
+++ b/Source/core/dom/EventTarget.cpp
@@ -212,11 +212,11 @@ bool EventTarget::fireEventListeners(Event* event)
             if (document->domWindow()) {
                 if (listenerPrefixedVector)
                     if (listenerUnprefixedVector)
-                        UseCounter::observe(document->domWindow(), UseCounter::PrefixedAndUnprefixedTransitionEndEvent);
+                        UseCounter::count(document->domWindow(), UseCounter::PrefixedAndUnprefixedTransitionEndEvent);
                     else
-                        UseCounter::observe(document->domWindow(), UseCounter::PrefixedTransitionEndEvent);
+                        UseCounter::count(document->domWindow(), UseCounter::PrefixedTransitionEndEvent);
                 else if (listenerUnprefixedVector)
-                    UseCounter::observe(document->domWindow(), UseCounter::UnprefixedTransitionEndEvent);
+                    UseCounter::count(document->domWindow(), UseCounter::UnprefixedTransitionEndEvent);
             }
         }
     }