Revert r21117 as it caused reliability failures....

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 # running overnight and removing outdated bugs/suppressions.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 737 matching lines @@
    Memcheck:Leak
    fun:_Znwj
    fun:_ZN7history20VisitSegmentDatabase17QuerySegmentUsageERKN4base4TimeEiPSt6vectorIP13PageUsageDataSaIS7_EE
    #fun:_ZN7history14HistoryBackend24QueryTopURLsAndRedirectsE13scoped_refptrI18CancelableRequest1I14CallbackRunnerI6Tuple2IPSt6vectorI4GURLSaIS6_EEPSt3mapIS6_S1_I16RefCountedVectorIS6_EESt4lessIS6_ESaISt4pairIKS6_SD_EEEEES4_IS8_SK_EEEi
 }
 {
    bug_16128
    Memcheck:Leak
    fun:_Znwj
    fun:_ZN3IPC11SyncChannelC1ERKSsNS_7Channel4ModeEPNS3_8ListenerEPNS_12ChannelProxy13MessageFilterEP11MessageLoopbPN4base13WaitableEventE
-   ...
-   fun:_ZN11ChildThreadC2Ev
-   fun:_ZN12RenderThreadC1Ev
-   fun:_Z12RendererMainRK18MainFunctionParams
+   fun:_ZN11ChildThread4InitEv
+   fun:_ZN12RenderThread4InitEv
 }
 {
    bug_16129
    Memcheck:Leak
    fun:_Znwj
    fun:_Z11NewCallbackI11WebViewImplPN11webkit_glue20ImageResourceFetcherERK8SkBitmapEPN9Callback2IT0_T1_E4TypeEPT_MSD_FvS8_S9_E
    fun:_ZN11WebViewImpl13DownloadImageEiRK4GURLi
    fun:_ZN10RenderView15OnDownloadImageEiRK4GURLi
 }
 {
@@ skipping 218 matching lines @@
    fun:_ZN3IPC7Channel11ChannelImplC1ERKSsNS0_4ModeEPNS0_8ListenerE
    fun:_ZN3IPC7ChannelC2ERKSsNS0_4ModeEPNS0_8ListenerE
    fun:_ZN3IPC7ChannelC1ERKSsNS0_4ModeEPNS0_8ListenerE
    fun:_ZN3IPC12ChannelProxy7Context13CreateChannelERKSsRKNS_7Channel4ModeE
    fun:_ZN3IPC12ChannelProxy4InitERKSsNS_7Channel4ModeEP11MessageLoopb
    fun:_ZN3IPC12ChannelProxyC2ERKSsNS_7Channel4ModeEP11MessageLoopPNS0_7ContextEb
    fun:_ZN3IPC11SyncChannelC2ERKSsNS_7Channel4ModeEPNS3_8ListenerEPNS_12ChannelProxy13MessageFilterEP11MessageLoopbPN4base13WaitableEventE
    fun:_ZN3IPC11SyncChannelC1ERKSsNS_7Channel4ModeEPNS3_8ListenerEPNS_12ChannelProxy13MessageFilterEP11MessageLoopbPN4base13WaitableEventE
    fun:_ZN11ChildThread4InitEv
 }