Oilpan: Move MediaStreamSource, MediaStreamComponent and MediaStreamDescriptor to oilpan's heap

public/web/WebHeap.h

Index: public/web/WebHeap.h
diff --git a/public/web/WebHeap.h b/public/web/WebHeap.h
index b8d01b3af2b514f86d2fea7a4044bb85a236d917..6f29367ac44ccb24ad2d653cad31afb0f857d02b 100644
--- a/public/web/WebHeap.h
+++ b/public/web/WebHeap.h
@@ -47,6 +47,12 @@ public:
         BLINK_EXPORT SafePointScope();
         BLINK_EXPORT ~SafePointScope();
     };
+
+    // These APIs are only for testing purposes and should not be used
+    // outside of tests.
+    static void collectGarbage();
+    static void collectGarbageWithNoPointersOnStack();
+    static void collectAllGarbage();
 };
 
 } // namespace blink