remove unnecessary heapcheck suppressions for sync unit tests

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 # running overnight and removing outdated bugs/suppressions.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 1334 matching lines @@
 {
    bug_80196
    Heapcheck:Leak
    fun:CallbackRunner* NewCallback
    fun:browser_sync::SyncBackendHost::ConfigureDataTypes
    fun:browser_sync::SyncBackendHostForProfileSyncTest::ConfigureDataTypes
    fun:browser_sync::DataTypeManagerImpl::Restart
    fun:browser_sync::DataTypeManagerImpl::Configure
 }
 {
-   bug_80238
-   Heapcheck:Leak
-   ...
-   fun:sync_notifier::::InvalidationNotifierTest::SetUp
-}
-{
    bug_80467
    Heapcheck:Leak
    ...
    fun:ExtensionService::RecordPermissionMessagesHistogram
 }
 {
    bug_80472
    Heapcheck:Leak
    ...
    fun:fileapi::::FileSystemURLRequestJobTest::SetUp
@@ skipping 193 matching lines @@
    ...
    fun:content_settings::PrefProviderTest_MigrateSinglePatternSettings_Test::TestBody
 }
 {
    bug_88212
    Heapcheck:Leak
    fun:TestingProfile::CreateRequestContext
    fun:ProfileSyncService*Test::SetUp
 }
 {
-   bug_88438
-   Heapcheck:Leak
-   fun:invalidation::NewPermanentCallback
-   fun:invalidation::InvalidationClientImpl::ScheduleStartAfterReadingStateBlob
-   fun:invalidation::InvalidationClientImpl::Start
-   fun:sync_notifier::ChromeInvalidationClient::Start
-}
-{
    bug_88640
    Heapcheck:Leak
    ...
    fun:ProfileImpl::DoFinalInit
    fun:ProfileImpl::OnPrefsLoaded
 }
 {
    bug_88735
    Heapcheck:Leak
    ...
@@ skipping 144 matching lines @@
    ...
    fun:::ReadManifest
    fun:ComponentUnpacker::ComponentUnpacker
 }
 {
    bug_91491
    Heapcheck:Leak
    ...
    fun:CrxUpdateService::ProcessPendingItems
 }