Partially revert r53873 (and the valgrind suppression for it).

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 # running overnight and removing outdated bugs/suppressions.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 3594 matching lines @@
 }
 {
    bug_50336
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN8syncable11UnpackEntryEP12SQLStatementPPNS_11EntryKernelE
    fun:_ZN8syncable21DirectoryBackingStore11LoadEntriesEPSt3setIPNS_11EntryKernelENS_9LessFieldINS_15MetahandleFieldELS5_0EEESaIS3_EE
    fun:*DirectoryBackingStore*
 }
 {
-   bug_50484
+   big_50484

[Evan Martin, 2010/07/28 17:56:48]

big?

    Memcheck:Leak
    ...
    fun:_ZN15SyncSetupWizard*EP18ProfileSyncService
    fun:_ZN18ProfileSyncService*
    fun:_ZN22ProfileSync*
    ...
    fun:*GetProfileSyncServiceEv
    fun:_ZN7Profile16IsSyncAccessibleEv
    fun:_ZN7Browser31UpdateCommandsForFullscreenModeEb
    fun:_ZN7Browser16InitCommandStateEv
    fun:_ZN7Browser*ENS_4TypeEP7Profile
 }
-{
-   bug_50504
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN25SharedResourcesDataSource8RegisterEv
-   fun:_Z27RegisterURLRequestChromeJobv
-   fun:_Z11BrowserMainRK18MainFunctionParams
-   fun:ChromeMain
-   fun:main
-}