Valgrind: Suppress a leak in HostContentSettingsMap.

tools/heapcheck/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 # running overnight and removing outdated bugs/suppressions.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 1727 matching lines @@
    fun:TabContentsContainer::ChangeTabContents
    fun:ConstrainedHtmlDelegateGtk
    fun:ConstrainedHtmlUI::CreateConstrainedHtmlDialog
    fun:printing::PrintPreviewTabController::CreatePrintPreviewTab
    fun:printing::PrintPreviewTabController::GetOrCreatePreviewTab
 #   fun:PrintPreviewHandlerTest_StickyMarginsCustomThenDefault_Test::TestBody
 #   fun:PrintPreviewTabControllerUnitTest_GetOrCreatePreviewTab_Test::TestBody
 #   fun:PrintPreviewTabControllerUnitTest_MultiplePreviewTabs_Test::TestBody
 #   fun:PrintPreviewTabControllerUnitTest_ClearInitiatorTabDetails_Test::TestBody
 }
+{
+   bug_104775
+   Heapcheck:Leak
+   fun:base::Value::CreateIntegerValue
+   fun:HostContentSettingsMap::SetDefaultContentSetting
+   fun:CookieSettings::SetDefaultCookieSetting
+   fun:ExtensionSpecialStoragePolicyTest_HasSessionOnlyOrigins_Test::TestBody
+}