Widen PrintPreviewTabControllerTest suppressions further.

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 # running overnight and removing outdated bugs/suppressions.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 3278 matching lines @@
    fun:_ZN7WebCore13StyledElement16attributeChangedEPNS_9AttributeEb
    fun:_ZN7WebCore10SVGElement16attributeChangedEPNS_9AttributeEb
    fun:_ZN7WebCore7Element12setAttributeERKNS_13QualifiedNameERKN3WTF12AtomicStringERi
    fun:_ZN7WebCore7Element14setAttributeNSERKN3WTF12AtomicStringES4_S4_RiNS_27FragmentScriptingPermissionE
    fun:_ZN7WebCore15ElementInternal22setAttributeNSCallbackERKN2v89ArgumentsE
 }
 {
    bug_66386_a
    Memcheck:Leak
    fun:_Znw*
+   ...
    fun:_ZN54PrintPreviewTabControllerTest_MultiplePreviewTabs_Test8TestBodyEv
 }
 {
    bug_66386_b
    Memcheck:Leak
    fun:_Znw*
+   ...
    fun:_ZN56PrintPreviewTabControllerTest_GetOrCreatePreviewTab_Test8TestBodyEv
 }