Fix Manifest leak in Extension::InitFromValue.

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 # running overnight and removing outdated bugs/suppressions.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 5304 matching lines @@
    fun:_ZN7WebCore8Document12updateLayoutEv
    fun:_ZN7WebCore8Document36updateLayoutIgnorePendingStylesheetsEv
    fun:_ZN7WebCore19ReplacementFragment30insertFragmentForTestRenderingEPNS_4NodeE
    fun:_ZN7WebCore19ReplacementFragmentC1EPNS_8DocumentEPNS_16DocumentFragmentEbRKNS_16VisibleSelectionE
    fun:_ZN7WebCore23ReplaceSelectionCommand7doApplyEv
    fun:_ZN7WebCore11EditCommand5applyEv
    fun:_ZN7WebCore12applyCommandEN3WTF10PassRefPtrINS_11EditCommandEEE
    fun:_ZN7WebCoreL21executeInsertFragmentEPNS_5FrameEN3WTF10PassRefPtrINS_16DocumentFragmentEEE
    fun:_ZN7WebCoreL17executeInsertHTMLEPNS_5FrameEPNS_5EventENS_19EditorCommandSourceERKN3WTF6StringE
 }
-{
-   bug_106331
-   Memcheck:Leak
-   ...
-   fun:_ZN9Extension6CreateERK8FilePathNS_8LocationERKN4base15DictionaryValueEiPSs
-}
 
 #-----------------------------------------------------------------------
 # 4. These only occur on our Google workstations
 {
    bug_todo_freeres
    Memcheck:Free
    fun:free
    fun:__libc_freeres
    fun:_vgnU_freeres
    fun:_Exit
@@ skipping 17 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
 }