Remove suppressions for fixed sync leaks.

tools/valgrind/memcheck/suppressions.txt

Index: tools/valgrind/memcheck/suppressions.txt
diff --git a/tools/valgrind/memcheck/suppressions.txt b/tools/valgrind/memcheck/suppressions.txt
index 08cdbb84ae8487a4f44e8b2f5c436d9133bddb33..a1a78fbfdf99b3af1969d72f820235fe7e510d4b 100644
--- a/tools/valgrind/memcheck/suppressions.txt
+++ b/tools/valgrind/memcheck/suppressions.txt
@@ -3576,42 +3576,6 @@
    fun:_ZN14RunnableMethodIN7history14HistoryBackendEMS1_FvbE6Tuple1IbEE3RunEv
 }
 {
-   bug_50334
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN9__gnu_cxx13new_allocatorISt13_Rb_tree_nodeISt4pairIKiN6google8protobuf8internal12ExtensionSet9ExtensionEEEE8allocateEjPKv
-   fun:_ZNSt8_Rb_treeIiSt4pairIKiN6google8protobuf8internal12ExtensionSet9ExtensionEESt10_Select1stIS7_ESt4lessIiESaIS7_EE11_M_get_nodeEv
-   fun:_ZNSt8_Rb_treeIiSt4pairIKiN6google8protobuf8internal12ExtensionSet9ExtensionEESt10_Select1stIS7_ESt4lessIiESaIS7_EE14_M_create_nodeERKS7_
-   fun:_ZNSt8_Rb_treeIiSt4pairIKiN6google8protobuf8internal12ExtensionSet9ExtensionEESt10_Select1stIS7_ESt4lessIiESaIS7_EE9_M_insertEPSt18_Rb_tree_node_baseSF_RKS7_
-   fun:_ZNSt8_Rb_treeIiSt4pairIKiN6google8protobuf8internal12ExtensionSet9ExtensionEESt10_Select1stIS7_ESt4lessIiESaIS7_EE16_M_insert_uniqueERKS7_
-   fun:_ZNSt3mapIiN6google8protobuf8internal12ExtensionSet9ExtensionESt4lessIiESaISt4pairIKiS4_EEE6insertERKS9_
-   fun:_ZN6google8protobuf8internal12ExtensionSet17MaybeNewExtensionEiPKNS0_15FieldDescriptorEPPNS2_9ExtensionE
-   fun:_ZN6google8protobuf8internal12ExtensionSet14MutableMessageEihRKNS0_11MessageLiteEPKNS0_15FieldDescriptorE
-   ...
-   fun:_ZN7sync_pb15EntitySpecifics*
-}
-{
-   bug_50335a
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN8syncable12MutableEntryC1EPNS_16WriteTransactionENS_19CreateNewUpdateItemERKNS_2IdE
-}
-{
-   bug_50335b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN8syncable12MutableEntry4InitEPNS_16WriteTransactionERKNS_2IdERKSs
-   fun:_ZN8syncable12MutableEntryC1EPNS_16WriteTransactionENS_6CreateERKNS_2IdERKSs
-}
-{
-   bug_50336
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN8syncable11UnpackEntryEP12SQLStatementPPNS_11EntryKernelE
-   fun:_ZN8syncable21DirectoryBackingStore11LoadEntriesEPSt3setIPNS_11EntryKernelENS_9LessFieldINS_15MetahandleFieldELS5_0EEESaIS3_EE
-   fun:*DirectoryBackingStore*
-}
-{
    bug_50484
    Memcheck:Leak
    ...