Suppress leaks in ManagedModeURLFilter

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 # running overnight and removing outdated bugs/suppressions.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 6434 matching lines @@
 }
 {
    bug_167481b
    Memcheck:Uninitialized
    ...
    fun:encode_frame_to_data_rate
    fun:vp8_get_compressed_data
    fun:vp8e_encode
    fun:vpx_codec_encode
 }
+{
+   bug_169042
+   Memcheck:Leak
+   ...
+   fun:_ZN6policy12URLBlacklist10AddFiltersEbPKN4base9ListValueE
+   fun:_ZN6policy12URLBlacklist5BlockEPKN4base9ListValueE
+   fun:_ZN20ManagedModeURLFilter14SetManualListsE10scoped_ptrIN4base9ListValueENS1_14DefaultDeleterIS2_EEES5_
+   fun:_ZN20ManagedModeURLFilterC1Ev
+   fun:_ZN11ManagedMode16URLFilterContextC1E13scoped_refptrIN4base19SequencedTaskRunnerEE
+   fun:_ZN11ManagedModeC2Ev
+}