Fix uninitialized read in the SimpleCache tests.

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 # running overnight and removing outdated bugs/suppressions.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 7322 matching lines @@
    fun:_ZN7content6Zygote17HandleReapRequestEiRK6Pickle14PickleIterator
    fun:_ZN7content6Zygote24HandleRequestFromBrowserEi
    fun:_ZN7content6Zygote15ProcessRequestsEv
    fun:_ZN7content10ZygoteMainERKNS_18MainFunctionParamsEPNS_18ZygoteForkDelegateE
    fun:_ZN7content9RunZygoteERKNS_18MainFunctionParamsEPNS_19ContentMainDelegateE
    fun:_ZN7content23RunNamedProcessTypeMainERKSsRKNS_18MainFunctionParamsEPNS_19ContentMainDelegateE
    fun:_ZN7content21ContentMainRunnerImpl3RunEv
    fun:_ZN7content11ContentMainEiPPKcPNS_19ContentMainDelegateE
 }
 {
-   bug_245952a
-   Memcheck:Uninitialized
-   fun:crc32_little
-   fun:MOZ_Z_crc32
-   fun:_ZN10disk_cache15SimpleEntryImpl17WriteDataInternalEiiPN3net8IOBufferEiRKN4base8CallbackIFviEEEb
-}
-{
-   bug_245952b
-   Memcheck:Param
-   pwrite64(buf)
-   obj:/lib/x86_64-linux-gnu/libpthread-2.15.so
-   fun:_ZN4base17WritePlatformFileEilPKci
-   fun:_ZN10disk_cache22SimpleSynchronousEntry9WriteDataEiiPN3net8IOBufferEibPi
-}
-{
    bug_245092a
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN10disk_cache14Mem*
    ...
    fun:_ZN11pnacl_cache31PNaClTranslationCacheWriteEntry12DispatchNextEi
    fun:_ZN11pnacl_cache31PNaClTranslationCacheWriteEntry9OpenEntryEv
    fun:_ZN11pnacl_cache31PNaClTranslationCacheWriteEntry5CacheEv
    fun:_ZN11pnacl_cache21PNaClTranslationCache9StoreNexeERKSsS2_RKN4base8CallbackIFviEEE
 }
@@ skipping 24 matching lines @@
    bug_246153
    Memcheck:Uninitialized
    fun:_ZN7WebCore8Settings29setOpenGLMultisamplingEnabledEb
    fun:_ZN6WebKit15WebSettingsImpl29setOpenGLMultisamplingEnabledEb
    fun:_ZN11webkit_glue19ApplyWebPreferencesERK14WebPreferencesPN6WebKit7WebViewE
    ...
    fun:_ZN7content14RenderViewImpl10InitializeEPNS_20RenderViewImplParamsE
    fun:_ZN7content14RenderViewImpl6CreateEiRKNS_19RendererPreferencesERK14WebPreferencesPN4base14RefCountedDataIiEEiiilRKSbItNS7_20string16_char_traitsESaItEEbbiRKN6WebKit13WebScreenInfoE17AccessibilityModeb
    fun:_ZN7content16RenderThreadImpl15OnCreateNewViewERK18ViewMsg_New_Params
 }