Suppress leaks in sync_file_system::SyncFileSystemBackend

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 # running overnight and removing outdated bugs/suppressions.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 867 matching lines @@
    fun:net::QuicPacketGenerator::SerializeAndSendPacket
    fun:net::QuicPacketGenerator::SendQueuedFrames
    fun:net::QuicPacketGenerator::AddControlFrame
    fun:net::QuicConnection::SendRstStream
    fun:net::QuicSession::SendRstStream
    fun:net::QuicClientSession::SendRstStream
    fun:net::ReliableQuicStream::Close
    fun:net::QuicHttpStream::Close
    fun:net::test::QuicStreamFactoryTest_MaxOpenStream_Test::TestBody
 }
+{
+   bug_282646
+   Heapcheck:Leak
+   ...
+   fun:SyncFileSystemBackend
+   fun:chrome::ChromeContentBrowserClient::GetAdditionalFileSystemBackends
+   fun:content::CreateFileSystemContext
+   fun:content::StoragePartitionImpl::Create
+   fun:content::StoragePartitionImplMap::Get
+   fun:GetStoragePartitionFromConfig
+   fun:content::BrowserContext::GetStoragePartitionForSite
+   fun:ExtensionService::NotifyExtensionUnloaded
+   fun:ExtensionService::UnloadExtension
+   fun:ExtensionService::AddExtension
+   fun:extensions::TestExtensionEnvironment::MakeExtension
+}