Attempt to fix ash tests on Chrome OS valgrind

tools/valgrind/memcheck/suppressions.txt

 # There are four 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 # running overnight and removing outdated bugs/suppressions.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 2999 matching lines @@
    fun:_ZN2cc10GLRenderer10DoDrawQuadEPNS_14DirectRenderer12DrawingFrameEPKNS_8DrawQuadEPKN3gfx5QuadFE
 }
 {
    bug_562431_a
    Memcheck:Leak
    fun:malloc
    fun:_ZN3WTF10Partitions10fastMallocEmPKc
    fun:_ZN5blink14PersistentBaseINS_15StyleFilterDataELNS_31WeaknessPersistentConfigurationE0ELNS_38CrossThreadnessPersistentConfigurationE0EEnwEm
    fun:_ZN5blink26RefCountedGarbageCollectedINS_15StyleFilterDataEE13makeKeepAliveEv
    fun:_ZN5blink26RefCountedGarbageCollectedINS_15StyleFilterDataEE3refEv
+   fun:_ZN3WTF6RefPtrIN5blink15StyleFilterDataEEC2IS2_EERKNS_6RawPtrIT_EEPNSt9enable_ifIXsr3std10is_base_ofIS2_S6_EE5valueEvE4typeE
    fun:_ZN5blink7DataRefINS_15StyleFilterDataEE4initEv
    fun:_ZN5blink13ComputedStyle18createInitialStyleEv
    fun:_ZN5blink13ComputedStyle19mutableInitialStyleEv
    fun:_ZN5blink13ComputedStyle12initialStyleEv
    fun:_ZN5blink13ComputedStyle6createEv
    fun:_ZN5blink13StyleResolver16styleForDocumentERNS_8DocumentE
    ...
    fun:_ZN5blink14DocumentLoader15finishedLoadingEd
    fun:_ZN5blink14DocumentLoader14maybeLoadEmptyEv
    fun:_ZN5blink14DocumentLoader24startLoadingMainResourceEv
@@ skipping 118 matching lines @@
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN4mojo3edk2js13HandleWrapper6Create*
    fun:_ZN3gin9ConverterIN4mojo6Handle*
    fun:_ZN3gin11ConvertToV8IN4mojo6Handle*
    fun:_ZN3gin10ToV8TraitsIN4mojo6HandleELb0EE14TryConvertToV8*
    fun:_ZN3gin14TryConvertToV8IN4mojo6Handle*
    fun:_ZN3gin10Dictionary3SetIN4mojo6Handle*
    fun:_ZN4mojo3edk2js12_GLOBAL__N_114CreateDataPipe*
 }