TSAN: Disable failing EmbeddedTestServerThreadingTestInstantiation 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 # running overnight and removing outdated bugs/suppressions.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 4301 matching lines @@
    Memcheck:Leak
    fun:malloc
    fun:get_peer_sock_name
    fun:_xcb_get_auth_info
    fun:xcb_connect_to_display_with_auth_info
    fun:_XConnectXCB
    fun:XOpenDisplay
    fun:_ZN4base18MessagePumpAuraX1118GetDefaultXDisplayEv
 }
 {
-   bug_147755_a
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN12PluginFinder18GetPluginInstallerERKN6webkit13WebPluginInfoE
-   fun:_ZN11PluginPrefs30EnablePluginIfPossibleCallbackE*
-}
-{
-   bug_147755_b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN12PluginFinder17GetPluginMetadataERKN6webkit13WebPluginInfoE
-   fun:_ZN11PluginPrefs12EnablePluginE*
-   fun:_ZN15PluginPrefsTest25EnablePluginSynchronouslyE*
-   fun:_ZN44PluginPrefsTest_UnifiedPepperFlashState_Test8TestBodyEv
-}
-{
    bug_149734a
    Memcheck:Leak
    fun:malloc
    fun:_ZN3WTF10fastMallocEm
    fun:_ZN3WTF16VectorBufferBaseIN7WebCore9AttributeEE14allocateBufferEm
    fun:_ZN3WTF12VectorBufferIN7WebCore9AttributeELm4EE14allocateBufferEm
    fun:_ZN3WTF6VectorIN7WebCore9AttributeELm4EE22reserveInitialCapacityEm
    fun:_ZN7WebCore20ElementAttributeData13cloneDataFromERKS0_RKNS_7ElementERS3_
 }
 {
@@ skipping 2008 matching lines @@
 }
 {
    bug_331925
    Memcheck:Leak
    ...
    fun:_ZN3net27TestURLRequestContextGetter20GetURLRequestContextEv
    fun:_ZN3net14URLFetcherCore30StartURLRequestWhenAppropriateEv
    fun:_ZN3net14URLFetcherCore19DidInitializeWriterEi
    fun:_ZN3net14URLFetcherCore15StartOnIOThreadEv
 }