ScreenshotTakerTest::TakeScreenshot test leaks

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 # running overnight and removing outdated bugs/suppressions.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 6908 matching lines @@
 }
 {
    bug_226254
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN4base4BindIMN10extensions16UserScriptMaster14ScriptReloader*
    fun:_ZN10extensions16UserScriptMaster14ScriptReloader9StartLoad*
    fun:_ZN10extensions16UserScriptMaster9StartLoadEv
    fun:_ZN10extensions16UserScriptMaster7ObserveEiRKN7content18NotificationSourceERKNS1_19NotificationDetailsE
 }
+{
+   bug_227271
+   Memcheck:Leak
+   fun:_Znw*
+   ...
+   fun:_ZN15ScreenshotTaker16ShowNotificationEN23ScreenshotTakerObserver6ResultERKN4base8FilePathE
+}