Remove the valgrind suppression in crbug.com/15762...

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 # running overnight and removing outdated bugs/suppressions.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 606 matching lines @@
 }
 {
    # See bug 12539 and 12549
    bug_12539
    Memcheck:Leak
    ...
    fun:_ZN7WebCore11ImageSource18createFrameAtIndexEj
    fun:_ZNK11webkit_glue12ImageDecoder6DecodeEPKhj
 }
 {
-   bug_15762
-   Memcheck:Cond
-   fun:_ZN7testing8internal11CmpHelperEQIjjEENS_15AssertionResultEPKcS4_RKT_RKT0_
-   ...
-   fun:_ZN39ImageOperations_CreateMaskedBitmap_Test8TestBodyEv
-}
-{
    # very common in ui tests
    bug_16089
    Memcheck:Leak
    fun:*
    fun:_ZN4base22LinuxDynamicThreadPool8PostTaskEP4Task
    ...
    fun:_ZN3net12HostResolver3Job5StartEv
 }
 {
    # ditto, but tweaked to fire on bots, more robust against optimizer changes?
@@ skipping 330 matching lines @@
   fun:_ZN11MessageLoop13RunAllPendingEv
   fun:_ZN46ExtensionsServiceTest_ExternalInstallPref_Test8TestBodyEv
   fun:_ZN7testing4Test3RunEv
   fun:_ZN7testing8internal12TestInfoImpl3RunEv
   fun:_ZN7testing8internal12TestInfoImpl7RunTestEPNS_8TestInfoE
   fun:_ZN7testing8TestCase3RunEv
   fun:_ZN7testing8TestCase11RunTestCaseEPS0_
   fun:_ZN7testing8internal12UnitTestImpl11RunAllTestsEv
   fun:_ZN7testing8UnitTest3RunEv
 }