Migrate chrome.bluetooth API backend to use device::BluetoothDiscoverySession.

Modified chrome.bluetooth API code to use the new discovery session API for
device discovery.

This CL is the same as r255262 which was reverted due to a memory leak. The leak
has been addressed in this patch.

BUG=346982,349942
TEST=1. Run unit_tests and browser_tests with LSan.
     2. Use multiple running extension instances with the bluetooth permission
        and check for the following behavior:
        - Only one session per extension. Calling chrome.bluetooth.stopDiscovery
          from one running app should fail if that app never called
          chrome.bluetooth.startDiscovery.
        - An app's discovery sessions should get cleaned up if that app crashes
          or unloads.
        - Use bt_console and run "power off". This should cause all discovery
          sessions that have been assigned to apps to get marked as inactive.
          Verify by requesting a new discovery session from apps, which should
          succeed.

Review URL: https://codereview.chromium.org/189463002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255609 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/api/bluetooth/bluetooth_api.cc

@@ -636,24 +636,18 @@ void BluetoothStartDiscoveryFunction::OnSuccessCallback() {
 
 void BluetoothStartDiscoveryFunction::OnErrorCallback() {
   SetError(kStartDiscoveryFailed);
-  GetEventRouter(browser_context())->SetResponsibleForDiscovery(false);
   SendResponse(false);
   GetEventRouter(browser_context())->OnListenerRemoved();
 }
 
 bool BluetoothStartDiscoveryFunction::DoWork(
     scoped_refptr<BluetoothAdapter> adapter) {
-  GetEventRouter(browser_context())->SetSendDiscoveryEvents(true);
-
-  // If this profile is already discovering devices, there should be nothing
-  // else to do.
-  if (!GetEventRouter(browser_context())->IsResponsibleForDiscovery()) {
-    GetEventRouter(browser_context())->SetResponsibleForDiscovery(true);
   GetEventRouter(browser_context())->OnListenerAdded();
-    adapter->StartDiscovering(
+  GetEventRouter(browser_context())->StartDiscoverySession(
+      adapter,
+      extension_id(),
       base::Bind(&BluetoothStartDiscoveryFunction::OnSuccessCallback, this),
       base::Bind(&BluetoothStartDiscoveryFunction::OnErrorCallback, this));
-  }
 
   return true;
 }
@@ -665,19 +659,17 @@ void BluetoothStopDiscoveryFunction::OnSuccessCallback() {
 
 void BluetoothStopDiscoveryFunction::OnErrorCallback() {
   SetError(kStopDiscoveryFailed);
-  GetEventRouter(browser_context())->SetResponsibleForDiscovery(true);
   SendResponse(false);
   GetEventRouter(browser_context())->OnListenerRemoved();
 }
 
 bool BluetoothStopDiscoveryFunction::DoWork(
     scoped_refptr<BluetoothAdapter> adapter) {
-  GetEventRouter(browser_context())->SetSendDiscoveryEvents(false);
-  if (GetEventRouter(browser_context())->IsResponsibleForDiscovery()) {
-    adapter->StopDiscovering(
+  GetEventRouter(browser_context())->StopDiscoverySession(
+      adapter,
+      extension_id(),
       base::Bind(&BluetoothStopDiscoveryFunction::OnSuccessCallback, this),
       base::Bind(&BluetoothStopDiscoveryFunction::OnErrorCallback, this));
-  }
 
   return true;
 }

chrome/browser/extensions/api/bluetooth/bluetooth_apitest.cc

@@ -17,16 +17,19 @@
 #include "device/bluetooth/bluetooth_out_of_band_pairing_data.h"
 #include "device/bluetooth/test/mock_bluetooth_adapter.h"
 #include "device/bluetooth/test/mock_bluetooth_device.h"
+#include "device/bluetooth/test/mock_bluetooth_discovery_session.h"
 #include "device/bluetooth/test/mock_bluetooth_profile.h"
 #include "device/bluetooth/test/mock_bluetooth_socket.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using device::BluetoothAdapter;
 using device::BluetoothDevice;
+using device::BluetoothDiscoverySession;
 using device::BluetoothOutOfBandPairingData;
 using device::BluetoothProfile;
 using device::MockBluetoothAdapter;
 using device::MockBluetoothDevice;
+using device::MockBluetoothDiscoverySession;
 using device::MockBluetoothProfile;
 using extensions::Extension;
 
@@ -65,6 +68,17 @@ class BluetoothApiTest : public ExtensionApiTest {
         false /* paired */, false /* connected */));
   }
 
+  void DiscoverySessionCallback(
+      const BluetoothAdapter::DiscoverySessionCallback& callback,
+      const BluetoothAdapter::ErrorCallback& error_callback) {
+    if (mock_session_.get()) {
+      callback.Run(
+          scoped_ptr<BluetoothDiscoverySession>(mock_session_.release()));
+      return;
+    }
+    error_callback.Run();
+  }
+
   template <class T>
   T* setupFunction(T* function) {
     function->set_extension(empty_extension_.get());
@@ -74,6 +88,7 @@ class BluetoothApiTest : public ExtensionApiTest {
 
  protected:
   testing::StrictMock<MockBluetoothAdapter>* mock_adapter_;
+  scoped_ptr<testing::NiceMock<MockBluetoothDiscoverySession> > mock_session_;
   scoped_ptr<testing::NiceMock<MockBluetoothDevice> > device1_;
   scoped_ptr<testing::NiceMock<MockBluetoothDevice> > device2_;
   scoped_ptr<testing::NiceMock<MockBluetoothProfile> > profile1_;
@@ -129,18 +144,11 @@ static bool CallClosure(const base::Closure& callback) {
   return true;
 }
 
-static void CallDiscoveryCallback(
-    const base::Closure& callback,
-    const BluetoothAdapter::ErrorCallback& error_callback) {
+static void StopDiscoverySessionCallback(const base::Closure& callback,
+                                         const base::Closure& error_callback) {
   callback.Run();
 }
 
-static void CallDiscoveryErrorCallback(
-    const base::Closure& callback,
-    const BluetoothAdapter::ErrorCallback& error_callback) {
-  error_callback.Run();
-}
-
 static void CallOutOfBandPairingDataCallback(
     const BluetoothAdapter::BluetoothOutOfBandPairingDataCallback& callback,
     const BluetoothAdapter::ErrorCallback& error_callback) {
@@ -316,9 +324,12 @@ IN_PROC_BROWSER_TEST_F(BluetoothApiTest, SetOutOfBandPairingData) {
 }
 
 IN_PROC_BROWSER_TEST_F(BluetoothApiTest, Discovery) {
-  // Try with a failure to start
-  EXPECT_CALL(*mock_adapter_, StartDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryErrorCallback));
+  // Try with a failure to start. This will return an error as we haven't
+  // initialied a session object.
+  EXPECT_CALL(*mock_adapter_, StartDiscoverySession(testing::_, testing::_))
+      .WillOnce(
+          testing::Invoke(this, &BluetoothApiTest::DiscoverySessionCallback));
+
   // StartDiscovery failure will remove the adapter that is no longer used.
   EXPECT_CALL(*mock_adapter_, RemoveObserver(testing::_));
   scoped_refptr<api::BluetoothStartDiscoveryFunction> start_function;
@@ -327,19 +338,28 @@ IN_PROC_BROWSER_TEST_F(BluetoothApiTest, Discovery) {
       utils::RunFunctionAndReturnError(start_function.get(), "[]", browser()));
   ASSERT_FALSE(error.empty());
 
-  // Reset for a successful start
+  // Reset the adapter and initiate a discovery session. The ownership of the
+  // mock session will be passed to the event router.
+  ASSERT_FALSE(mock_session_.get());
   SetUpMockAdapter();
-  EXPECT_CALL(*mock_adapter_, StartDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryCallback));
 
+  // Create a mock session to be returned as a result. Get a handle to it as
+  // its ownership will be passed and |mock_session_| will be reset.
+  mock_session_.reset(new testing::NiceMock<MockBluetoothDiscoverySession>());
+  MockBluetoothDiscoverySession* session = mock_session_.get();
+  EXPECT_CALL(*mock_adapter_, StartDiscoverySession(testing::_, testing::_))
+      .WillOnce(
+          testing::Invoke(this, &BluetoothApiTest::DiscoverySessionCallback));
   start_function = setupFunction(new api::BluetoothStartDiscoveryFunction);
   (void)
       utils::RunFunctionAndReturnError(start_function.get(), "[]", browser());
 
-  // Reset to try stopping
+  // End the discovery session. The StopDiscovery function should succeed.
   testing::Mock::VerifyAndClearExpectations(mock_adapter_);
-  EXPECT_CALL(*mock_adapter_, StopDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryCallback));
+  EXPECT_CALL(*session, IsActive()).WillOnce(testing::Return(true));
+  EXPECT_CALL(*session, Stop(testing::_, testing::_))
+      .WillOnce(testing::Invoke(StopDiscoverySessionCallback));
+
   // StopDiscovery success will remove the adapter that is no longer used.
   EXPECT_CALL(*mock_adapter_, RemoveObserver(testing::_));
   scoped_refptr<api::BluetoothStopDiscoveryFunction> stop_function;
@@ -347,10 +367,10 @@ IN_PROC_BROWSER_TEST_F(BluetoothApiTest, Discovery) {
   (void) utils::RunFunctionAndReturnSingleResult(
       stop_function.get(), "[]", browser());
 
-  // Reset to try stopping with an error
+  // Reset the adapter. Simulate failure for stop discovery. The event router
+  // still owns the session. Make it appear inactive.
   SetUpMockAdapter();
-  EXPECT_CALL(*mock_adapter_, StopDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryErrorCallback));
+  EXPECT_CALL(*session, IsActive()).WillOnce(testing::Return(false));
   EXPECT_CALL(*mock_adapter_, RemoveObserver(testing::_));
   stop_function = setupFunction(new api::BluetoothStopDiscoveryFunction);
   error =
@@ -360,10 +380,14 @@ IN_PROC_BROWSER_TEST_F(BluetoothApiTest, Discovery) {
 }
 
 IN_PROC_BROWSER_TEST_F(BluetoothApiTest, DiscoveryCallback) {
-  EXPECT_CALL(*mock_adapter_, StartDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryCallback));
-  EXPECT_CALL(*mock_adapter_, StopDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryCallback));
+  mock_session_.reset(new testing::NiceMock<MockBluetoothDiscoverySession>());
+  MockBluetoothDiscoverySession* session = mock_session_.get();
+  EXPECT_CALL(*mock_adapter_, StartDiscoverySession(testing::_, testing::_))
+      .WillOnce(
+          testing::Invoke(this, &BluetoothApiTest::DiscoverySessionCallback));
+  EXPECT_CALL(*session, IsActive()).WillOnce(testing::Return(true));
+  EXPECT_CALL(*session, Stop(testing::_, testing::_))
+      .WillOnce(testing::Invoke(StopDiscoverySessionCallback));
 
   ResultCatcher catcher;
   catcher.RestrictToProfile(browser()->profile());
@@ -408,17 +432,22 @@ IN_PROC_BROWSER_TEST_F(BluetoothApiTest, DiscoveryInProgress) {
   ResultCatcher catcher;
   catcher.RestrictToProfile(browser()->profile());
 
-  EXPECT_CALL(*mock_adapter_, StartDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryCallback));
-  EXPECT_CALL(*mock_adapter_, StopDiscovering(testing::_, testing::_))
-      .WillOnce(testing::Invoke(CallDiscoveryCallback));
+  mock_session_.reset(new testing::NiceMock<MockBluetoothDiscoverySession>());
+  MockBluetoothDiscoverySession* session = mock_session_.get();
+  EXPECT_CALL(*mock_adapter_, StartDiscoverySession(testing::_, testing::_))
+      .WillOnce(
+          testing::Invoke(this, &BluetoothApiTest::DiscoverySessionCallback));
+  EXPECT_CALL(*session, IsActive()).WillOnce(testing::Return(true));
+  EXPECT_CALL(*session, Stop(testing::_, testing::_))
+      .WillOnce(testing::Invoke(StopDiscoverySessionCallback));
 
   ExtensionTestMessageListener discovery_started("ready", true);
   ASSERT_TRUE(LoadExtension(
         test_data_dir_.AppendASCII("bluetooth/discovery_in_progress")));
   EXPECT_TRUE(discovery_started.WaitUntilSatisfied());
 
-  // This should be received in addition to the cached device above.
+  // Only this should be received. No additional notification should be sent for
+  // devices discovered before the discovery session started.
   event_router()->DeviceAdded(mock_adapter_, device2_.get());
 
   discovery_started.Reply("go");

chrome/browser/extensions/api/bluetooth/bluetooth_event_router.cc

@@ -22,6 +22,7 @@
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_adapter_factory.h"
 #include "device/bluetooth/bluetooth_device.h"
+#include "device/bluetooth/bluetooth_discovery_session.h"
 #include "device/bluetooth/bluetooth_profile.h"
 #include "device/bluetooth/bluetooth_socket.h"
 #include "extensions/browser/event_router.h"
@@ -45,9 +46,7 @@ struct ExtensionBluetoothProfileRecord {
 
 ExtensionBluetoothEventRouter::ExtensionBluetoothEventRouter(
     content::BrowserContext* context)
-    : send_discovery_events_(false),
-      responsible_for_discovery_(false),
-      browser_context_(context),
+    : browser_context_(context),
       adapter_(NULL),
       num_event_listeners_(0),
       next_socket_id_(1),
@@ -72,6 +71,11 @@ ExtensionBluetoothEventRouter::~ExtensionBluetoothEventRouter() {
        ++iter) {
     iter->second.profile->Unregister();
   }
+  for (DiscoverySessionMap::iterator iter = discovery_session_map_.begin();
+       iter != discovery_session_map_.end();
+       ++iter) {
+    delete iter->second;
+  }
 }
 
 bool ExtensionBluetoothEventRouter::IsBluetoothSupported() const {
@@ -145,6 +149,50 @@ bool ExtensionBluetoothEventRouter::HasProfile(const std::string& uuid) const {
   return bluetooth_profile_map_.find(uuid) != bluetooth_profile_map_.end();
 }
 
+void ExtensionBluetoothEventRouter::StartDiscoverySession(
+    device::BluetoothAdapter* adapter,
+    const std::string& extension_id,
+    const base::Closure& callback,
+    const base::Closure& error_callback) {
+  if (adapter != adapter_.get()) {
+    error_callback.Run();
+    return;
+  }
+  DiscoverySessionMap::iterator iter =
+      discovery_session_map_.find(extension_id);
+  if (iter != discovery_session_map_.end() && iter->second->IsActive()) {
+    DVLOG(1) << "An active discovery session exists for extension.";
+    error_callback.Run();
+    return;
+  }
+  adapter->StartDiscoverySession(
+      base::Bind(&ExtensionBluetoothEventRouter::OnStartDiscoverySession,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 extension_id,
+                 callback),
+      error_callback);
+}
+
+void ExtensionBluetoothEventRouter::StopDiscoverySession(
+    device::BluetoothAdapter* adapter,
+    const std::string& extension_id,
+    const base::Closure& callback,
+    const base::Closure& error_callback) {
+  if (adapter != adapter_.get()) {
+    error_callback.Run();
+    return;
+  }
+  DiscoverySessionMap::iterator iter =
+      discovery_session_map_.find(extension_id);
+  if (iter == discovery_session_map_.end() || !iter->second->IsActive()) {
+    DVLOG(1) << "No active discovery session exists for extension.";
+    error_callback.Run();
+    return;
+  }
+  device::BluetoothDiscoverySession* session = iter->second;
+  session->Stop(callback, error_callback);
+}
+
 device::BluetoothProfile* ExtensionBluetoothEventRouter::GetProfile(
     const std::string& uuid) const {
   BluetoothProfileMap::const_iterator iter = bluetooth_profile_map_.find(uuid);
@@ -162,29 +210,6 @@ ExtensionBluetoothEventRouter::GetSocket(int id) {
   return socket_entry->second.socket;
 }
 
-void ExtensionBluetoothEventRouter::SetResponsibleForDiscovery(
-    bool responsible) {
-  responsible_for_discovery_ = responsible;
-}
-
-bool ExtensionBluetoothEventRouter::IsResponsibleForDiscovery() const {
-  return responsible_for_discovery_;
-}
-
-void ExtensionBluetoothEventRouter::SetSendDiscoveryEvents(bool should_send) {
-  // At the transition into sending devices, also send past devices that
-  // were discovered as they will not be discovered again.
-  if (should_send && !send_discovery_events_) {
-    for (DeviceList::const_iterator i = discovered_devices_.begin();
-        i != discovered_devices_.end(); ++i) {
-      DispatchDeviceEvent(extensions::event_names::kBluetoothOnDeviceDiscovered,
-                          **i);
-    }
-  }
-
-  send_discovery_events_ = should_send;
-}
-
 void ExtensionBluetoothEventRouter::DispatchDeviceEvent(
     const std::string& event_name, const bluetooth::Device& device) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
@@ -243,9 +268,19 @@ void ExtensionBluetoothEventRouter::AdapterDiscoveringChanged(
   }
 
   if (!discovering) {
-    send_discovery_events_ = false;
-    responsible_for_discovery_ = false;
-    discovered_devices_.clear();
+    // If any discovery sessions are inactive, clean them up.
+    DiscoverySessionMap active_session_map;
+    for (DiscoverySessionMap::iterator iter = discovery_session_map_.begin();
+         iter != discovery_session_map_.end();
+         ++iter) {
+      device::BluetoothDiscoverySession* session = iter->second;
+      if (session->IsActive()) {
+        active_session_map[iter->first] = session;
+        continue;
+      }
+      delete session;
+    }
+    discovery_session_map_.swap(active_session_map);
   }
 
   DispatchAdapterStateEvent();
@@ -259,17 +294,11 @@ void ExtensionBluetoothEventRouter::DeviceAdded(
     return;
   }
 
-  bluetooth::Device* extension_device =
-      new bluetooth::Device();
-  bluetooth::BluetoothDeviceToApiDevice(
-      *device, extension_device);
-  discovered_devices_.push_back(extension_device);
-
-  if (!send_discovery_events_)
-    return;
+  bluetooth::Device extension_device;
+  bluetooth::BluetoothDeviceToApiDevice(*device, &extension_device);
 
   DispatchDeviceEvent(extensions::event_names::kBluetoothOnDeviceDiscovered,
-                      *extension_device);
+                      extension_device);
 }
 
 void ExtensionBluetoothEventRouter::InitializeAdapterIfNeeded() {
@@ -331,6 +360,27 @@ void ExtensionBluetoothEventRouter::CleanUpForExtension(
       ReleaseSocket(socket_id);
     }
   }
+
+  // Remove any discovery session initiated by the extension.
+  DiscoverySessionMap::iterator session_iter =
+      discovery_session_map_.find(extension_id);
+  if (session_iter == discovery_session_map_.end())
+    return;
+  delete session_iter->second;
+  discovery_session_map_.erase(session_iter);
+}
+
+void ExtensionBluetoothEventRouter::OnStartDiscoverySession(
+    const std::string& extension_id,
+    const base::Closure& callback,
+    scoped_ptr<device::BluetoothDiscoverySession> discovery_session) {
+  // Clean up any existing session instance for the extension.
+  DiscoverySessionMap::iterator iter =
+      discovery_session_map_.find(extension_id);
+  if (iter != discovery_session_map_.end())
+    delete iter->second;
+  discovery_session_map_[extension_id] = discovery_session.release();
+  callback.Run();
 }
 
 void ExtensionBluetoothEventRouter::Observe(

chrome/browser/extensions/api/bluetooth/bluetooth_event_router.h

@@ -24,6 +24,7 @@ class BrowserContext;
 namespace device {
 
 class BluetoothDevice;
+class BluetoothDiscoverySession;
 class BluetoothProfile;
 
 }  // namespace device
@@ -81,6 +82,25 @@ class ExtensionBluetoothEventRouter
   // registered.
   bool HasProfile(const std::string& uuid) const;
 
+  // Requests that a new device discovery session be initiated for extension
+  // with id |extension_id|. |callback| is called, if a session has been
+  // initiated. |error_callback| is called, if the adapter failed to initiate
+  // the session or if an active session already exists for the extension.
+  void StartDiscoverySession(device::BluetoothAdapter* adapter,
+                             const std::string& extension_id,
+                             const base::Closure& callback,
+                             const base::Closure& error_callback);
+
+  // Requests that the active discovery session that belongs to the extension
+  // with id |extension_id| be terminated. |callback| is called, if the session
+  // successfully ended. |error_callback| is called, if the adapter failed to
+  // terminate the session or if no active discovery session exists for the
+  // extension.
+  void StopDiscoverySession(device::BluetoothAdapter* adapter,
+                            const std::string& extension_id,
+                            const base::Closure& callback,
+                            const base::Closure& error_callback);
+
   // Returns the BluetoothProfile that corresponds to |uuid|. It returns NULL
   // if the BluetoothProfile with |uuid| does not exist.
   device::BluetoothProfile* GetProfile(const std::string& uuid) const;
@@ -88,14 +108,6 @@ class ExtensionBluetoothEventRouter
   // Get the BluetoothSocket corresponding to |id|.
   scoped_refptr<device::BluetoothSocket> GetSocket(int id);
 
-  // Sets whether this Profile is responsible for the discovering state of the
-  // adapter.
-  void SetResponsibleForDiscovery(bool responsible);
-  bool IsResponsibleForDiscovery() const;
-
-  // Sets whether or not DeviceAdded events will be dispatched to extensions.
-  void SetSendDiscoveryEvents(bool should_send);
-
   // Dispatch an event that takes a device as a parameter to all renderers.
   void DispatchDeviceEvent(
       const std::string& event_name,
@@ -127,15 +139,17 @@ class ExtensionBluetoothEventRouter
   void SetAdapterForTest(device::BluetoothAdapter* adapter) {
     adapter_ = adapter;
   }
+
  private:
   void InitializeAdapterIfNeeded();
   void InitializeAdapter(scoped_refptr<device::BluetoothAdapter> adapter);
   void MaybeReleaseAdapter();
   void DispatchAdapterStateEvent();
   void CleanUpForExtension(const std::string& extension_id);
-
-  bool send_discovery_events_;
-  bool responsible_for_discovery_;
+  void OnStartDiscoverySession(
+      const std::string& extension_id,
+      const base::Closure& callback,
+      scoped_ptr<device::BluetoothDiscoverySession> discovery_session);
 
   content::BrowserContext* browser_context_;
   scoped_refptr<device::BluetoothAdapter> adapter_;
@@ -150,15 +164,16 @@ class ExtensionBluetoothEventRouter
   typedef std::map<int, ExtensionBluetoothSocketRecord> SocketMap;
   SocketMap socket_map_;
 
-  typedef ScopedVector<extensions::api::bluetooth::Device>
-      DeviceList;
-  DeviceList discovered_devices_;
-
   // A map that maps uuids to ExtensionBluetoothProfileRecord.
   typedef std::map<std::string, ExtensionBluetoothProfileRecord>
       BluetoothProfileMap;
   BluetoothProfileMap bluetooth_profile_map_;
 
+  // A map that maps extension ids to BluetoothDiscoverySession pointers.
+  typedef std::map<std::string, device::BluetoothDiscoverySession*>
+      DiscoverySessionMap;
+  DiscoverySessionMap discovery_session_map_;
+
   content::NotificationRegistrar registrar_;
 
   base::WeakPtrFactory<ExtensionBluetoothEventRouter> weak_ptr_factory_;

chrome/test/data/extensions/api_test/bluetooth/discovery_in_progress/runtest.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-var kExpectedDeviceNames = ["d1", "d2"];
+var kExpectedDeviceNames = ["d2"];
 
 function testDiscovery() {
   chrome.test.assertEq(kExpectedDeviceNames.length,

device/bluetooth/bluetooth.gyp

@@ -123,6 +123,8 @@
         'test/mock_bluetooth_adapter.h',
         'test/mock_bluetooth_device.cc',
         'test/mock_bluetooth_device.h',
+        'test/mock_bluetooth_discovery_session.cc',
+        'test/mock_bluetooth_discovery_session.h',
         'test/mock_bluetooth_profile.cc',
         'test/mock_bluetooth_profile.h',
         'test/mock_bluetooth_socket.cc',

device/bluetooth/bluetooth_adapter.cc

@@ -113,7 +113,7 @@ void BluetoothAdapter::OnStartDiscoverySession(
     const DiscoverySessionCallback& callback) {
   VLOG(1) << "Discovery session started!";
   scoped_ptr<BluetoothDiscoverySession> discovery_session(
-      new BluetoothDiscoverySession(this));
+      new BluetoothDiscoverySession(scoped_refptr<BluetoothAdapter>(this)));
   discovery_sessions_.insert(discovery_session.get());
   callback.Run(discovery_session.Pass());
 }

device/bluetooth/bluetooth_discovery_session.cc

@@ -9,13 +9,21 @@
 
 namespace device {
 
-BluetoothDiscoverySession::BluetoothDiscoverySession(BluetoothAdapter* adapter)
-    : active_(true),
-      adapter_(adapter),
-      weak_ptr_factory_(this) {
+BluetoothDiscoverySession::BluetoothDiscoverySession(
+    scoped_refptr<BluetoothAdapter> adapter)
+    : active_(true), adapter_(adapter), weak_ptr_factory_(this) {
+  DCHECK(adapter_.get());
 }
 
+BluetoothDiscoverySession::BluetoothDiscoverySession()
+    : active_(false), weak_ptr_factory_(this) {}
+
 BluetoothDiscoverySession::~BluetoothDiscoverySession() {
+  // |adapter_| may be NULL if this instance was initialized as a mock.
+  if (!adapter_.get()) {
+    DCHECK(!active_);
+    return;
+  }
   Stop(base::Bind(&base::DoNothing), base::Bind(&base::DoNothing));
   adapter_->DiscoverySessionDestroyed(this);
 }
@@ -28,11 +36,12 @@ void BluetoothDiscoverySession::Stop(
     const base::Closure& callback,
     const ErrorCallback& error_callback) {
   if (!active_) {
-    LOG(ERROR) << "Discovery session not active. Cannot stop.";
+    LOG(WARNING) << "Discovery session not active. Cannot stop.";
     error_callback.Run();
     return;
   }
   VLOG(1) << "Stopping device discovery session.";
+  DCHECK(adapter_.get());
   adapter_->RemoveDiscoverySession(
       base::Bind(&BluetoothDiscoverySession::OnStop,
                  weak_ptr_factory_.GetWeakPtr(),

device/bluetooth/bluetooth_discovery_session.h

@@ -58,10 +58,12 @@ class BluetoothDiscoverySession {
                     const ErrorCallback& error_callback);
 
  protected:
-  friend class BluetoothAdapter;
-  explicit BluetoothDiscoverySession(BluetoothAdapter* adapter);
+  BluetoothDiscoverySession();  // Called by mock.
 
  private:
+  friend class BluetoothAdapter;
+  explicit BluetoothDiscoverySession(scoped_refptr<BluetoothAdapter> adapter);
+
   // Internal callback invoked when a call to Stop has succeeded.
   void OnStop(const base::Closure& callback);
 

device/bluetooth/test/mock_bluetooth_adapter.cc

@@ -14,4 +14,12 @@ MockBluetoothAdapter::MockBluetoothAdapter() {
 
 MockBluetoothAdapter::~MockBluetoothAdapter() {}
 
+void MockBluetoothAdapter::AddDiscoverySession(
+    const base::Closure& callback,
+    const ErrorCallback& error_callback) {}
+
+void MockBluetoothAdapter::RemoveDiscoverySession(
+    const base::Closure& callback,
+    const ErrorCallback& error_callback) {}
+
 }  // namespace device

device/bluetooth/test/mock_bluetooth_adapter.h

@@ -52,6 +52,9 @@ class MockBluetoothAdapter : public BluetoothAdapter {
                     const base::Closure& callback,
                     const ErrorCallback& error_callback));
   MOCK_CONST_METHOD0(IsDiscovering, bool());
+  MOCK_METHOD2(StartDiscoverySession,
+               void(const DiscoverySessionCallback& callback,
+                    const ErrorCallback& error_callback));
   MOCK_METHOD2(StartDiscovering,
                void(const base::Closure& callback,
                     const ErrorCallback& error_callback));
@@ -74,12 +77,10 @@ class MockBluetoothAdapter : public BluetoothAdapter {
   MOCK_METHOD0(DefaultPairingDelegate, BluetoothDevice::PairingDelegate*());
 
  protected:
-  MOCK_METHOD2(AddDiscoverySession,
-               void(const base::Closure& callback,
-                    const ErrorCallback& error_callback));
-  MOCK_METHOD2(RemoveDiscoverySession,
-               void(const base::Closure& callback,
-                    const ErrorCallback& error_callback));
+  virtual void AddDiscoverySession(const base::Closure& callback,
+                                   const ErrorCallback& error_callback);
+  virtual void RemoveDiscoverySession(const base::Closure& callback,
+                                      const ErrorCallback& error_callback);
   virtual ~MockBluetoothAdapter();
 
   MOCK_METHOD1(RemovePairingDelegateInternal,

device/bluetooth/test/mock_bluetooth_discovery_session.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "device/bluetooth/test/mock_bluetooth_discovery_session.h"
+
+#include "device/bluetooth/bluetooth_adapter.h"
+
+namespace device {
+
+MockBluetoothDiscoverySession::MockBluetoothDiscoverySession() {}
+MockBluetoothDiscoverySession::~MockBluetoothDiscoverySession() {}
+
+}  // namespace device

device/bluetooth/test/mock_bluetooth_discovery_session.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef DEVICE_BLUETOOTH_TEST_MOCK_BLUETOOTH_DISCOVERY_SESSION_H_
+#define DEVICE_BLUETOOTH_TEST_MOCK_BLUETOOTH_DISCOVERY_SESSION_H_
+
+#include "base/callback.h"
+#include "device/bluetooth/bluetooth_discovery_session.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace device {
+
+class BluetoothAdapter;
+
+class MockBluetoothDiscoverySession : public BluetoothDiscoverySession {
+ public:
+  MockBluetoothDiscoverySession();
+  virtual ~MockBluetoothDiscoverySession();
+
+  MOCK_CONST_METHOD0(IsActive, bool());
+  MOCK_METHOD2(Stop,
+               void(const base::Closure& callback,
+                    const ErrorCallback& error_callback));
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MockBluetoothDiscoverySession);
+};
+
+}  // namespac device
+
+#endif  // DEVICE_BLUETOOTH_TEST_MOCK_BLUETOOTH_DISCOVERY_SESSION_H_