Fix memory leaks in TopSites.

tools/valgrind/memcheck/suppressions.txt

 # There are three 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 # running overnight and removing outdated bugs/suppressions.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 3531 matching lines @@
    bug_50056
    Memcheck:Leak
    fun:_Znw*
    fun:_Z11NewCallbackI22ContentSettingsHandlerPK5ValueEPN9Callback1IT0_E4TypeEPT_MS9_FvS5_E
    fun:_ZN22ContentSettingsHandler16RegisterMessagesEv
    fun:_ZN17DOMMessageHandler6AttachEP5DOMUI
    fun:_ZN9OptionsUI23AddOptionsPageUIHandlerEP15DictionaryValueP20OptionsPageUIHandler
    fun:_ZN9OptionsUIC1EP11TabContents
    fun:_Z8NewDOMUII9OptionsUIEP5DOMUIP11TabContentsRK4GURL
 }
-{
-   bug_50103_a
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN5Value15CreateNullValueEv
-   fun:_ZN7history8TopSites17AddBlacklistedURLERK4GURL
-   fun:_ZN7history*TopSitesTest_*_Test8TestBodyEv
-}
-{
-   bug_50103_b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN5Value18CreateIntegerValueE*
-   fun:_ZN7history8TopSites12AddPinnedURLERK4GURL*
-   fun:_ZN7history*TopSitesTest_PinnedURLs_Test8TestBodyEv
-}