Add UMA for the number of devices in the chooser when a device is paired

chrome/browser/ui/bluetooth/bluetooth_chooser_controller_unittest.cc

 // Copyright 2016 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 <string>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h"
@@ skipping 21 matching lines @@
 };
 
 }  // namespace
 
 class BluetoothChooserControllerTest : public testing::Test {
  public:
   BluetoothChooserControllerTest()
       : bluetooth_chooser_controller_(
             nullptr,
             base::Bind(&BluetoothChooserControllerTest::OnBluetoothChooserEvent,
-                       base::Unretained(this))) {
+                       base::Unretained(this)),
+            true /* accept_all_devices */) {
     bluetooth_chooser_controller_.set_view(&mock_bluetooth_chooser_view_);
   }
 
  protected:
   void OnBluetoothChooserEvent(content::BluetoothChooser::Event event,
                                const std::string& device_id) {
     last_event_ = event;
     last_device_id_ = device_id;
   }
 
@@ skipping 310 matching lines @@
   EXPECT_EQ(content::BluetoothChooser::Event::CANCELLED, last_event_);
   EXPECT_EQ(std::string(), last_device_id_);
 }
 
 TEST_F(BluetoothChooserControllerWithDevicesAddedTest,
        CloseShouldCallEventHandler) {
   bluetooth_chooser_controller_.Close();
   EXPECT_EQ(content::BluetoothChooser::Event::CANCELLED, last_event_);
   EXPECT_EQ(std::string(), last_device_id_);
 }