Initialize the CPU usage variable.

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 # running overnight and removing outdated bugs/suppressions.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 5262 matching lines @@
    fun:_ZN7WebCore7Element13computedStyleENS_8PseudoIdE
    fun:_ZN7WebCore16HTMLTitleElement17textWithDirectionEv
    fun:_ZN7WebCore16HTMLTitleElement15childrenChangedEbPNS_4NodeES2_i
    fun:_ZN7WebCore13ContainerNode14parserAddChildEN3WTF10PassRefPtrINS_4NodeEEE
    fun:_ZN7WebCore20HTMLConstructionSite12attachAtSiteERKNS0_14AttachmentSiteEN3WTF10PassRefPtrINS_4NodeEEE
    fun:_ZN7WebCore20HTMLConstructionSite14insertTextNodeERKN3WTF6StringE
    fun:_ZN7WebCore15HTMLTreeBuilder22processCharacterBufferERNS0_28ExternalCharacterTokenBufferE
    fun:_ZN7WebCore15HTMLTreeBuilder16processCharacterERNS_15AtomicHTMLTokenE
 }
 {
-   bug_106067
-   Memcheck:Uninitialized
-   fun:_ZN16RenderThreadImpl26IdleHandlerInForegroundTabEv
-   fun:_ZN16RenderThreadImpl11IdleHandlerEv
-}
-{
    bug_106104
    Memcheck:Unaddressable
    ...
    fun:_ZN3WTF14deleteOwnedPtrIN7WebCore27InspectorBaseAgentInterfaceEEEvPT_
    fun:_ZN3WTF6OwnPtrIN7WebCore27InspectorBaseAgentInterfaceEED1Ev
    fun:_ZN3WTF16VectorDestructorILb1ENS_6OwnPtrIN7WebCore27InspectorBaseAgentInterfaceEEEE8destructEPS4_S6_
    fun:_ZN3WTF20VectorTypeOperationsINS_6OwnPtrIN7WebCore27InspectorBaseAgentInterfaceEEEE8destructEPS4_S6_
 }
 
 #-----------------------------------------------------------------------
@@ skipping 25 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
 }