Fix memory leak in SequencedWorkerPool

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 # running overnight and removing outdated bugs/suppressions.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 5912 matching lines @@
    bug_115808_a
    Memcheck:Uninitialized
    fun:_ZN7WebCore18HarfBuzzShaperBase25determineWordBreakSpacingEv
 }
 {
    bug_115808_b
    Memcheck:Uninitialized
    fun:_ZN7WebCore18HarfBuzzShaperBase10setPaddingEi
    fun:_ZN7WebCore21ComplexTextController*
 }
-{
-   bug_115987
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN4base12_GLOBAL__N_123SequencedWorkerPoolTestC2Ev
-   fun:_ZN4base*SequencedWorkerPoolTest_*
-   fun:_ZN7testing8internal15TestFactoryImplIN4base*SequencedWorkerPoolTest_*
-}
+
 
 #-----------------------------------------------------------------------
 # 4. These only occur on our Google workstations
 
 {
    bug_todo_getdelim
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    ...
    fun:call_init
    fun:_dl_init
 }
 {
    bug_todo_getdelim2
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }