Do not open or close IOHIDManager's IOHIDDeviceRefs.

device/hid/hid_connection_mac.cc

Index: device/hid/hid_connection_mac.cc
diff --git a/device/hid/hid_connection_mac.cc b/device/hid/hid_connection_mac.cc
index e06994c049d35268fad1d57cd7c1da945d7e2d35..d743aebdf3f0252ab3e539c8211fdd90858f6f82 100644
--- a/device/hid/hid_connection_mac.cc
+++ b/device/hid/hid_connection_mac.cc
@@ -17,21 +17,27 @@ HidConnectionMac::HidConnectionMac(HidDeviceInfo device_info)
   message_loop_ = base::MessageLoopProxy::current();
 
   DCHECK(device_.get());
+
   size_t expected_report_size = device_info.max_input_report_size;
   if (device_info.has_report_id) {
     expected_report_size++;
   }
-  inbound_buffer_.reset(new uint8_t[expected_report_size]);
-  IOHIDDeviceRegisterInputReportCallback(device_.get(),
-                                         inbound_buffer_.get(),
-                                         expected_report_size,
-                                         &HidConnectionMac::InputReportCallback,
-                                         this);
-  IOHIDDeviceOpen(device_, kIOHIDOptionsTypeNone);
+  inbound_buffer_.resize(expected_report_size);
+  if (inbound_buffer_.size() > 0) {
+    IOHIDDeviceRegisterInputReportCallback(
+        device_.get(),
+        &inbound_buffer_[0],
+        inbound_buffer_.size(),
+        &HidConnectionMac::InputReportCallback,
+        this);
+  }
 }
 
 HidConnectionMac::~HidConnectionMac() {
-  IOHIDDeviceClose(device_, kIOHIDOptionsTypeNone);
+  if (inbound_buffer_.size() > 0) {
+    IOHIDDeviceRegisterInputReportCallback(

[Ken Rockot(use gerrit already), 2014/09/13 01:36:17]

Can you please comment on why this is done? I do not understand.

[Reilly Grant (use Gerrit), 2014/09/13 05:05:05]

Registering a NULL callback clears the input report callback this is necessary
so that no callbacks occur after the HidConnectMac has been freed.

+        device_.get(), &inbound_buffer_[0], inbound_buffer_.size(), NULL, this);
+  }
   Flush();
 }
 
@@ -72,6 +78,7 @@ void HidConnectionMac::PlatformGetFeatureReport(uint8_t report_id,
   if (result == kIOReturnSuccess) {
     callback.Run(true, buffer, report_size);
   } else {
+    VLOG(1) << "Failed to get feature report: " << result;
     callback.Run(false, NULL, 0);
   }
 }
@@ -90,6 +97,11 @@ void HidConnectionMac::InputReportCallback(void* context,
                                            uint32_t report_id,
                                            uint8_t* report_bytes,
                                            CFIndex report_length) {
+  if (result != kIOReturnSuccess) {
+    VLOG(1) << "Failed to read input report: " << result;
+    return;
+  }
+
   HidConnectionMac* connection = static_cast<HidConnectionMac*>(context);
   scoped_refptr<net::IOBufferWithSize> buffer;
   if (connection->device_info().has_report_id) {
@@ -131,6 +143,7 @@ void HidConnectionMac::WriteReport(IOHIDReportType type,
   if (res == kIOReturnSuccess) {
     callback.Run(true);
   } else {
+    VLOG(1) << "Failed to set report: " << res;
     callback.Run(false);
   }
 }