Clean up MFYI by adding suppressions for new bugs

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 # running overnight and removing outdated bugs/suppressions.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 6076 matching lines @@
    fun:_ZNK7WebCore18StyleSheetContents11isCacheableEv
    fun:_ZN7WebCore9LinkStyle16setCSSStyleSheetERKN3WTF6StringERKNS_4KURLES4_PKNS_21CSSStyleSheetResourceE
    fun:_ZN7WebCore21CSSStyleSheetResource11checkNotifyEv
    ...
    fun:_ZN11webkit_glue16WebURLLoaderImpl7Context18OnCompletedRequestEibRKSsRKN4base9TimeTicksE
 }
 {
    bug_329960
    Memcheck:Leak
    fun:_Znw*
-   fun:_ZN7WebCore22V8PerContextDataHolder7installEN2v86HandleINS1_7ContextEEE
+   fun:_ZN7WebCore22V8PerContextDataHolder7installE*
    fun:_ZN7WebCore22WorkerScriptController25initializeContextIfNeededEv
    ...
    fun:_ZN7WebCore12WorkerThread12workerThreadEv
 }
 {
    bug_331061
    Memcheck:Unaddressable
    fun:_ZNK3WTF6RefPtrIN7WebCore14SecurityOriginEE3getEv
    fun:_ZNK7WebCore15SecurityContext14securityOriginEv
    fun:_ZN7WebCore13V8WindowShell16setSecurityTokenEv
@@ skipping 211 matching lines @@
    fun:_mesa_CopyTexSubImage2D
    fun:shared_dispatch_stub_326
    fun:_ZN3gfx9GLApiBase21glCopyTexSubImage2DFnEjiiiiiii
    fun:_ZN3gpu5gles216GLES2DecoderImpl19DoCopyTexSubImage2DEjiiiiiii
    fun:_ZN3gpu5gles216GLES2DecoderImpl23HandleCopyTexSubImage2DEjRKNS0_4cmds17CopyTexSubImage2DE
    fun:_ZN3gpu5gles216GLES2DecoderImpl9DoCommandEjjPKv
    fun:_ZN3gpu13CommandParser14ProcessCommandEv
    fun:_ZN3gpu12GpuScheduler10PutChangedEv
    fun:_ZN3gpu22InProcessCommandBuffer12PumpCommandsEv
 }
+{
+   bug_348629
+   Memcheck:Leak
+   fun:_Znw*
+   fun:_ZN7WebCore11ThreadStateC1Ev
+   fun:_ZN7WebCore11ThreadState6attachEv
+   fun:_ZN7WebCore12WorkerThread12workerThreadEv
+   fun:_ZN7WebCore12WorkerThread17workerThreadStartEPv
+   fun:_ZN3WTFL16threadEntryPointEPv
+   fun:_ZN3WTFL19wtfThreadEntryPointEPv
+}
+{
+   bug_348630
+   Memcheck:Leak
+   fun:_Zna*
+   fun:_ZN7content30WebKitPlatformSupportChildImpl18waitMultipleEventsERKN5blink9WebVectorIPNS1_16WebWaitableEventEEE
+}