Valgrind suppression updates for Mac UI bots

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 # running overnight and removing outdated bugs/suppressions.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 1048 matching lines @@
    fun:malloc
    fun:g_malloc
    fun:g_slice_alloc
    fun:handlers_find
    fun:signal_handlers_foreach_matched_R
    fun:g_signal_handlers_disconnect_matched
    fun:gtk_accel_label_set_accel_widget
    fun:gtk_accel_label_destroy
 }
 {
-   bug_20580
-   Memcheck:Addr1
-   fun:syncJournal
-   fun:sqlite3PagerCommitPhaseOne
-   fun:sqlite3BtreeCommitPhaseOne
-   fun:vdbeCommit
-   fun:sqlite3VdbeHalt
-   fun:sqlite3VdbeExec
-   fun:sqlite3Step
-   fun:sqlite3_step
-   fun:sqlite3_exec
-   fun:_ZN7history16ArchivedDatabase17CommitTransactionEv
-}
-{
    bug_20581
    Memcheck:Leak
    ...
    fun:btreeCreateTable
    fun:sqlite3BtreeCreateTable
    fun:sqlite3VdbeExec
    fun:sqlite3Step
    fun:sqlite3_step
    fun:sqlite3_exec
 }
@@ skipping 41 matching lines @@
    bug_20778
    Memcheck:Cond
    fun:_ZN7WebCore10XSSAuditor23CachingURLCanonicalizer15canonicalizeURLERKNS_6StringERKNS_12TextEncodingEb
 }
 {
    bug_20805
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN7history14HistoryBackend12AddPageVisitERK4GURLN4base4TimeExj
 }