Implement basic parts of hit regions on canvas2d.

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 415e15916e72377cce1fceaeaabc3bddac49ce0b..93d51830260e5b82533f981d58dcea32b22f2bf3 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -87,6 +87,7 @@
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLSelectElement.h"
 #include "core/html/HTMLTextAreaElement.h"
+#include "core/html/canvas/CanvasRenderingContext2D.h"
 #include "core/html/forms/FormController.h"
 #include "core/html/shadow/ShadowElementNames.h"
 #include "core/html/shadow/TextControlInnerElements.h"
@@ -2374,4 +2375,9 @@ void Internals::setNetworkConnectionInfo(const String& type, ExceptionState& exc
     networkStateNotifier().setWebConnectionTypeForTest(webtype);
 }
 
+unsigned Internals::countHitRegions(CanvasRenderingContext2D* context)
+{
+    return context->hitRegionsCount();
+}
+
 } // namespace WebCore