Use IOService enumeration instead of IOHIDManager in HidServiceMac.

Using the IOServiceAddMatchingNotification API to monitor devices
connected to the system is preferable to IOHIDManager because it is
lighter weight. IOHIDManager forces its own lifetime expectations on
the IOHIDDevice objects that it creates and opens all devices it sees
for I/O whether or not there is a Chrome app that is using them.

As a necessary step to simplify this transition the device/hid API now
lives on the browser UI thread when running on OS X. This change will
soon be made for Linux and Windows as well. This change should also
reduce the risk of race conditions as observed in bug 418207 which is
why it is being made independently of the other platforms.

BUG=418207,413978
R=rockot@chromium.org,rpaquay@chromium.org
TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/637863003

Cr-Commit-Position: refs/heads/master@{#298793}

1 files changed, 3 insertions, 1 deletions

diff --git a/device/hid/hid_connection_unittest.cc b/device/hid/hid_connection_unittest.cc
index 28e136c..903cf5a 100644
--- a/device/hid/hid_connection_unittest.cc
+++ b/device/hid/hid_connection_unittest.cc
@@ -73,7 +73,9 @@ class HidConnectionTest : public testing::Test {
     if (!UsbTestGadget::IsTestEnabled()) return;
 
     message_loop_.reset(new base::MessageLoopForIO());
-    service_ = HidService::GetInstance(message_loop_->message_loop_proxy());
+    service_ = HidService::GetInstance(
+        message_loop_->message_loop_proxy(),
+        message_loop_->message_loop_proxy());
     ASSERT_TRUE(service_);
 
     test_gadget_ = UsbTestGadget::Claim();