Add suppression for occasional leak in IPC::Channel::Connect().

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 # running overnight and removing outdated bugs/suppressions.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 922 matching lines @@
    ...
    fun:_ZN3IPC12ChannelProxy7Context13CreateChannelERKSsRKNS_7Channel4ModeE
    fun:_ZN3IPC12ChannelProxy4InitERKSsNS_7Channel4ModeEP11MessageLoopb
    fun:_ZN3IPC12ChannelProxyC2ERKSsNS_7Channel4ModeEP11MessageLoopPNS0_7ContextEb
    fun:_ZN3IPC11SyncChannelC1ERKSsNS_7Channel4ModeEPNS3_8ListenerEPNS_12ChannelProxy13MessageFilterEP11MessageLoopbPN4base13WaitableEventE
    fun:_ZN11ChildThread4InitEv
    fun:_ZN11ChildThreadC2ESs
    fun:_ZN12RenderThreadC1ERKSs
 }
 {
+   bug_17540
+   Memcheck:Leak
+   fun:_Znwj
+   fun:_ZN4base19MessagePumpLibevent19WatchFileDescriptorEibNS0_4ModeEPNS0_21FileDescriptorWatcherEPNS0_7WatcherE
+   fun:_ZN16MessageLoopForIO19WatchFileDescriptorEibNS_4ModeEPN4base19MessagePumpLibevent21FileDescriptorWatcherEPNS2_7WatcherE
+   fun:_ZN3IPC7Channel11ChannelImpl7ConnectEv
+   fun:_ZN3IPC7Channel7ConnectEv
+   fun:_ZN3IPC12ChannelProxy7Context15OnChannelOpenedEv
+}
+{
    bug_17795
    Memcheck:Leak
    fun:_Znwj
    fun:_ZN3WTF9HashTableIPN7WebCore13QualifiedName17QualifiedNameImplES4_NS_17IdentityExtractorIS4_EENS1_17QualifiedNameHashENS_10HashTraitsIS4_EES9_E18addPassingHashCodeINS1_23QualifiedNameComponentsESC_NS_24HashSetTranslatorAdapterIS4_S9_SC_NS1_25QNameComponentsTranslatorEEEEESt4pairINS_17HashTableIteratorIS4_S4_S6_S7_S9_S9_EEbERKT_RKT0_
    fun:_ZN3WTF7HashSetIPN7WebCore13QualifiedName17QualifiedNameImplENS1_17QualifiedNameHashENS_10HashTraitsIS4_EEE3addINS1_23QualifiedNameComponentsENS1_25QNameComponentsTranslatorEEESt4pairINS_24HashTableIteratorAdapterINS_9HashTableIS4_S4_NS_17IdentityExtractorIS4_EES5_S7_S7_EES4_EEbERKT_
    fun:_ZN7WebCore13QualifiedNameC1ERKNS_12AtomicStringES3_S3_
    fun:_ZN7WebCore8SVGNames4initEv
 }