Widen one suppression to match linux bot, add one new suppression for mac....

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 # running overnight and removing outdated bugs/suppressions.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 978 matching lines @@
    Memcheck:Free
    fun:_ZdlPv
    fun:_ZN7WebCore15CSSSelectorList19adoptSelectorVectorERN3WTF6VectorIPNS_11CSSSelectorELj0EEE
    fun:_Z10cssyyparsePv
    fun:_ZN7WebCore9CSSParser13parseSelectorERKNS_6StringEPNS_8DocumentERNS_15CSSSelectorListE
 }
 {
    bug_19191
    Memcheck:Leak
    ...
-   fun:_ZN7WebCore10StringImplC1EPKcjj
    fun:_ZN3WTF9HashTableIPN7WebCore10StringImplES3_NS_17IdentityExtractorIS3_EENS1_10StringHashENS_10HashTraitsIS3_EES8_E18addPassingHashCodeIPKcSC_NS_24HashSetTranslatorAdapterIS3_S8_SC_NS1_17CStringTranslatorEEEEESt4pairINS_17HashTableIteratorIS3_S3_S5_S6_S8_S8_EEbERKT_RKT0_
    fun:_ZN3WTF7HashSetIPN7WebCore10StringImplENS1_10StringHashENS_10HashTraitsIS3_EEE3addIPKcNS1_17CStringTranslatorEEESt4pairINS_24HashTableIteratorAdapterINS_9HashTableIS3_S3_NS_17IdentityExtractorIS3_EES4_S6_S6_EES3_EEbERKT_
    fun:_ZN7WebCore12AtomicString3addEPKc
    fun:_ZN7WebCore10XLinkNames4initEv
 }
 {
    bug_19196
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN2v817RegisterExtensionEPNS_9ExtensionE
@@ skipping 97 matching lines @@
    Memcheck:Leak
    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_group_disconnect
    fun:gtk_accel_group_disconnect_key
 }