More valgrind suppressions

tools/valgrind/memcheck/suppressions_mac.txt

 # There are three kinds of suppressions in this file:
 # 1. Third party stuff we have no control over.
 #
 # 2. Intentional unit test errors, 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.
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 535 matching lines @@
    Memcheck:Leak
    fun:_Znwm
    fun:_ZN4base19MessagePumpLibevent19WatchFileDescriptorEibNS0_4ModeEPNS0_21FileDescriptorWatcherEPNS0_7WatcherE
    fun:_ZN16MessageLoopForIO19WatchFileDescriptorEibNS_4ModeEPN4base19MessagePumpLibevent21FileDescriptorWatcherEPNS2_7WatcherE
    fun:_ZN3IPC7Channel11ChannelImpl23ProcessOutgoingMessagesEv
 }
 {
    # Strange...
    bug_20653a
    Memcheck:Param
+   write(buf)
    ...
    fun:sqlite3OsWrite
    fun:pager_write_pagelist
    fun:sqlite3PagerCommitPhaseOne
 }
 {
    # Strange...
    bug_20653b
    Memcheck:Addr4
    fun:sqlite3MemSize
@@ skipping 81 matching lines @@
    fun:_ZN7history16ArchivedDatabase17CommitTransactionEv
    fun:_ZN7history16ArchivedDatabase4InitERK8FilePath
 }
 {
    bug_20837
    Memcheck:Leak
    fun:malloc
    fun:sqlite3MemMalloc
    fun:mallocWithAlarm
    ...
-   fun:_ZN7history11URLDatabase27InitKeywordSearchTermsTableEv
    fun:_ZN7history16ArchivedDatabase4InitERK8FilePath
 }