Explicitly ShutdownOnUIThread the HostContentSettingsMap when destroying the Profile.

tools/valgrind/memcheck/suppressions.txt

 # There are three 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 # running overnight and removing outdated bugs/suppressions.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 3310 matching lines @@
    fun:_ZN19SafeBrowsingService5StartEv
    fun:_ZN19SafeBrowsingService10InitializeEv
    fun:_ZN22ResourceDispatcherHost10InitializeEv
    fun:_ZN18BrowserProcessImpl28CreateResourceDispatcherHostEv
    fun:_ZN18BrowserProcessImpl24resource_dispatcher_hostEv
    fun:_ZN16ExtensionService4InitEv
    fun:_ZN11ProfileImpl14InitExtensionsE*
    fun:_ZN14ProfileManager10AddProfileEP7Profileb
 }
 {
-   bug_66853_b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN11ProfileImpl25GetHostContentSettingsMapEv
-   ...
-   fun:_ZNK17ProfileImplIOData6Handle27GetMainRequestContextGetterEv
-   fun:_ZN11ProfileImpl17GetRequestContextEv
-   fun:_ZN19SafeBrowsingService5StartEv
-   fun:_ZN19SafeBrowsingService10InitializeEv
-   fun:_ZN22ResourceDispatcherHost10InitializeEv
-   fun:_ZN18BrowserProcessImpl28CreateResourceDispatcherHostEv
-   fun:_ZN18BrowserProcessImpl24resource_dispatcher_hostEv
-   fun:_ZN16ExtensionService4InitEv
-   fun:_ZN11ProfileImpl14InitExtensionsE*
-   fun:_ZN14ProfileManager10AddProfileEP7Profileb
-}
-{
    bug_67142
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN16ChildProcessHost13CreateChannelEv
    fun:_ZN14GpuProcessHost4InitEv
 }
 {
    bug_67261
    Memcheck:Leak
    fun:_Znw*
@@ skipping 1438 matching lines @@
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN8chromeos12input_method14IBusController6CreateEv
    fun:_ZN8chromeos12input_method22InputMethodManagerImplC1Ev
    fun:_ZN22DefaultSingletonTraitsIN8chromeos12input_method22InputMethodManagerImplEE3NewEv
    fun:_ZN9SingletonIN8chromeos12input_method22InputMethodManagerImplE22DefaultSingletonTraitsIS2_ES2_E3getEv
    fun:_ZN8chromeos12input_method22InputMethodManagerImpl11GetInstanceEv
    fun:_ZN8chromeos12input_method18InputMethodManager11GetInstanceEv
 }
 
-{
-  bug_88557
-  Memcheck:Leak
-  fun:_Znw*
-  fun:_ZN14ExtensionPrefsC1EP11PrefServiceRK8FilePathP21ExtensionPrefValueMap
-  fun:_ZN11ProfileImpl13OnPrefsLoadedEb
-  fun:_ZN11ProfileImplC1ERK8FilePathPN7Profile8DelegateE
-  fun:_ZN7Profile13CreateProfileERK8FilePath
-  fun:_ZN14ProfileManager10GetProfileERK8FilePath
-  fun:_ZN14ProfileManager17GetDefaultProfileERK8FilePath
-  fun:_ZN12_GLOBAL__N_113CreateProfileERK18MainFunctionParamsRK8FilePath
-  fun:_Z11BrowserMainRK18MainFunctionParams
-  fun:_ZN12_GLOBAL__N_123RunNamedProcessTypeMainERKSsRK18MainFunctionParams
-  fun:ChromeMain
-  fun:main
-}
-
 #-----------------------------------------------------------------------
 # These only occur on our Google workstations
 {
    bug_todo_freeres
    Memcheck:Free
    fun:free
    fun:__libc_freeres
    fun:_vgnU_freeres
    fun:_Exit
    fun:exit
@@ skipping 10 matching lines @@
 {
    bug_todo_getdelim2
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }