Fixed memory leaks in download manager 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 # running overnight and removing outdated bugs/suppressions.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 1592 matching lines @@
    fun:net::ConnectJob::Connect
    fun:net::internal::ClientSocketPoolBaseHelper::RequestSocketInternal
    fun:net::internal::ClientSocketPoolBaseHelper::RequestSocket
    fun:net::ClientSocketPoolBase::RequestSocket
    fun:net::TransportClientSocketPool::RequestSocket
    fun:net::ClientSocketHandle::Init
    fun:net::::InitSocketPoolHelper
    fun:net::ClientSocketPoolManager::InitSocketHandleForRawConnect
    fun:notifier::ProxyResolvingClientSocket::ProcessProxyResolveDone
 }
-{
-   bug_83638a
-   Heapcheck:Leak
-   fun:DownloadManagerTest_*_Test::TestBody
-   fun:testing::internal::HandleSehExceptionsInMethodIfSupported
-   fun:testing::internal::HandleExceptionsInMethodIfSupported
-   fun:testing::Test::Run
-}
-{
-   bug_83638b
-   Heapcheck:Leak
-   fun:__gnu_cxx::new_allocator::allocate
-   fun:std::_Vector_base::_M_allocate
-   fun:std::vector::_M_insert_aux
-   fun:std::vector::push_back
-   fun:DownloadManagerTest_*_Test::TestBody
-   fun:testing::internal::HandleSehExceptionsInMethodIfSupported
-   fun:testing::internal::HandleExceptionsInMethodIfSupported
-   fun:testing::Test::Run
-}
-{
-   bug_83638c
-   Heapcheck:Leak
-   fun:__gnu_cxx::new_allocator::allocate
-   fun:std::string::_Rep::_S_create
-   fun:std::string::_Rep::_M_clone
-   fun:std::string::reserve
-   fun:bool ::InitCanonical
-   fun:GURL::GURL
-   fun:DownloadManagerTest_StartDownload_Test::TestBody
-   fun:testing::internal::HandleSehExceptionsInMethodIfSupported
-   fun:testing::internal::HandleExceptionsInMethodIfSupported
-   fun:testing::Test::Run
-}
-{
-   bug_83638d
-   Heapcheck:Leak
-   fun:__gnu_cxx::new_allocator::allocate
-   fun:std::string::_Rep::_S_create
-   fun:std::string::_M_mutate
-   fun:std::string::_M_replace_safe
-   fun:std::string::assign
-   fun:std::string::assign
-   fun:std::string::operator=
-   fun:DownloadManagerTest_StartDownload_Test::TestBody
-   fun:testing::internal::HandleSehExceptionsInMethodIfSupported
-   fun:testing::internal::HandleExceptionsInMethodIfSupported
-   fun:testing::Test::Run
-}