Fix webkit_media::WebMediaPlayerProxy memory leak due to circular refcounting.

tools/valgrind/memcheck/suppressions.txt

 # There are four kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 4679 matching lines @@
    fun:_ZN7WebCore11RenderBlock11layoutBlockEbiNS0_15BlockLayoutPassE
    fun:_ZN7WebCore11RenderBlock6layoutEv
 }
 {
    bug_100330
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN25TestingAutomationProvider42NavigateToURLBlockUntilNavigationsCompleteEiRK4GURLiPN3IPC7MessageE
 }
 {
-   bug_100583
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN11webkit_media18WebMediaPlayerImpl10InitializeEPN6WebKit8WebFrameEb13scoped_refptrINS_16WebVideoRendererEE
-   ...
-   fun:_ZN6WebKitL20createWebMediaPlayerEPNS_20WebMediaPlayerClientEPN7WebCore5FrameE
-   fun:_ZN6WebKit24WebMediaPlayerClientImpl12loadInternalEv
-   fun:_ZN6WebKit24WebMediaPlayerClientImpl4loadERKN3WTF6StringE
-   fun:_ZN7WebCore11MediaPlayer23loadWithNextMediaEngineEPNS_18MediaPlayerFactoryE
-   fun:_ZN7WebCore11MediaPlayer4loadERKN3WTF6StringERKNS_11ContentTypeE
-   fun:_ZN7WebCore16HTMLMediaElement12loadResourceERKNS_4KURLERNS_11ContentTypeE
-   ...
-   fun:_ZN7WebCore16HTMLMediaElement19selectMediaResourceEv
-   fun:_ZN7WebCore16HTMLMediaElement12loadInternalEv
-   fun:_ZN7WebCore16HTMLMediaElement14loadTimerFiredEPNS_5TimerIS0_EE
-   fun:_ZN7WebCore5TimerINS_16HTMLMediaElementEE5firedEv
-}
-{
    bug_100608
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN27SQLitePersistentCookieStore7Backend21LoadCookiesForDomainsERKSt3setISsSt4lessISsESaISsEE
 }
 {
    bug_100647
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN18WebResourceService19UpdateResourceCacheERKSs
@@ skipping 539 matching lines @@
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }