Adding unittest for the reference counting of WebMediaStreamDescriptor/Source

tools/heapcheck/suppressions.txt

Index: tools/heapcheck/suppressions.txt
diff --git a/tools/heapcheck/suppressions.txt b/tools/heapcheck/suppressions.txt
index fc335214438d21b0740fc35872add1105e59b91d..de744795249c1771b9a4004d38ab52ec2bdfe169 100644
--- a/tools/heapcheck/suppressions.txt
+++ b/tools/heapcheck/suppressions.txt
@@ -1715,15 +1715,6 @@
    fun:PeerConnectionHandlerTest_Basic_Test::TestBody
 }
 {
-   bug_105624_b
-   Heapcheck:Leak
-   fun:WTF::fastMalloc
-   fun:WTF::RefCounted::operator new
-   fun:WebCore::MediaStreamSource::create
-   fun:WebKit::WebMediaStreamSource::initialize
-   fun:PeerConnectionHandlerTest_Basic_Test::TestBody
-}
-{
    bug_105624_c
    Heapcheck:Leak
    fun:WTF::fastMalloc
@@ -1830,14 +1821,4 @@
    fun:ResourceDispatcherHostTest::MakeTestRequest
    fun:ResourceDispatcherHostTest_*_Test::TestBody
 }
-{
-   bug_111757
-   Heapcheck:Leak
-   fun:WTF::fastMalloc
-   ...
-   fun:PeerConnectionHandler::CreateWebKitStreamDescriptor
-   fun:PeerConnectionHandler::OnAddStreamCallback
-   fun:PeerConnectionHandler::OnAddStream
-   fun:PeerConnectionHandlerTest_Basic_Test::TestBody
-}