Suppressed memory leaks in ipc_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 # running overnight and removing outdated bugs/suppressions.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 65 matching lines @@
    bug_30547
    Heapcheck:Leak
    fun:std::string::_Rep::_S_create
    fun:base::JSONWriter::Write
    fun:JSONStringValueSerializer::Serialize
    fun:BookmarkStorage::SerializeData
    fun:BookmarkStorage::SaveNow
    fun:BookmarkStorage::BookmarkModelDeleted
    fun:BookmarkModel::~BookmarkModel
 }
+# IPCChannelTest.ChannelProxyTest leaks memory.
+{
+   bug_26920_a
+   Heapcheck:Leak
+   fun:IPC::ChannelProxy::ChannelProxy
+   fun:IPCChannelTest_ChannelProxyTest_Test::TestBody
+}
+# TODO(glider): deal with asterisks in stack traces
+# (like "CancelableTask* NewRunnableMethod" here)
+{
+   bug_26920_b
+   Heapcheck:Leak
+   ...
+   fun:IPC::ChannelProxy::Context::OnChannelError
+   fun:IPC::Channel::ChannelImpl::OnFileCanReadWithoutBlocking
+   fun:base::MessagePumpLibevent::OnLibeventNotification
+   fun:event_process_active
+   fun:event_base_loop
+}
+{
+   bug_26920_c
+   Heapcheck:Leak
+   fun:__gnu_cxx::new_allocator::allocate
+   fun:std::string::_Rep::_S_create
+   ...
+   fun:std::basic_string::basic_string
+   fun:IPCChannelTest_ChannelProxyTest_Test::TestBody
+}