Make EventHandler::ActiveIntervalTimer mockable.

Source/core/testing/Internals.h

Index: Source/core/testing/Internals.h
diff --git a/Source/core/testing/Internals.h b/Source/core/testing/Internals.h
index 9891956f5ee3e904c3b2c77bb768bd0a78c646e6..aa24f4a0faf8220ddad2230dd1f3d2ad14da74bc 100644
--- a/Source/core/testing/Internals.h
+++ b/Source/core/testing/Internals.h
@@ -177,6 +177,9 @@ public:
     Node* touchNodeAdjustedToBestContextMenuNode(long x, long y, long width, long height, Document*, ExceptionState&);
     PassRefPtr<ClientRect> bestZoomableAreaForTouchPoint(long x, long y, long width, long height, Document*, ExceptionState&);
 
+    void setActiveIntervalTimerInManualMode(Document*, bool, ExceptionState&);
+    void fireActiveIntervalTimer(Document*, ExceptionState&);
+
     int lastSpellCheckRequestSequence(Document*, ExceptionState&);
     int lastSpellCheckProcessedSequence(Document*, ExceptionState&);