Remove suppression for unused variable now that CCVideoLayerImpl is fixed.

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 # running overnight and removing outdated bugs/suppressions.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 5767 matching lines @@
    fun:_ZN3net16HostResolverImpl3Job18OnProcTaskCompleteEiRKNS_11AddressListE
 }
 {
    bug_118336
    Memcheck:Leak
    fun:_Znw*
    ...
    fun:_ZN47SelectFileDialogExtensionTest_SelfDeleting_Test8TestBodyEv
 }
 {
-   bug_118384
-   Memcheck:Uninitialized
-   fun:_ZN7WebCore16CCVideoLayerImpl11appendQuadsERNS_12CCQuadCullerEPKNS_17CCSharedQuadStateE
-   fun:_ZN7WebCore12CCRenderPass19appendQuadsForLayerEPNS_11CCLayerImplEPNS_22CCOcclusionTrackerBaseIS1_NS_15CCRenderSurfaceEEEPNS_16CCOverdrawCountsE
-   fun:_ZN7WebCore19CCLayerTreeHostImpl21calculateRenderPassesERN3WTF6VectorINS1_6OwnPtrINS_12CCRenderPassEEELm0EEERNS2_IPNS_11CCLayerImplELm0EEE
-   fun:_ZN7WebCore19CCLayerTreeHostImpl10drawLayersEv
-   fun:_ZN7WebCore19CCSingleThreadProxy11doCompositeEv
-}
-{
    bug_118387a
    Memcheck:Unaddressable
    fun:_ZN3WTF11currentTimeEv
    fun:_ZN7WebCore5EventC2ERKN3WTF12AtomicStringEbb
    fun:_ZN7WebCore19PageTransitionEventC1ERKN3WTF12AtomicStringEb
    fun:_ZN7WebCore19PageTransitionEvent6createERKN3WTF12AtomicStringEb
    fun:_ZN7WebCore11FrameLoader11stopLoadingENS_17UnloadEventPolicyE
    fun:_ZN7WebCore11FrameLoader8closeURLEv
    fun:_ZN7WebCore11FrameLoader16detachFromParentEv
    fun:_ZN7WebCore11FrameLoader13frameDetachedEv
@@ skipping 36 matching lines @@
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }