Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/signin/chrome_identity_service_observer_bridge_unittest.mm

 // Copyright 2015 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.
 
 #import "ios/chrome/browser/signin/chrome_identity_service_observer_bridge.h"
 
+#include <memory>
+
 #include "base/mac/scoped_nsobject.h"
-#include "base/memory/scoped_ptr.h"
 #import "ios/public/provider/chrome/browser/signin/chrome_identity.h"
 #include "ios/public/provider/chrome/browser/signin/chrome_identity_service.h"
 #include "testing/gtest_mac.h"
 #include "testing/platform_test.h"
 
 @interface TestChromeIdentityServiceObserver
     : NSObject<ChromeIdentityServiceObserver>
 @property(nonatomic) BOOL onIdentityListChangedCalled;
 @property(nonatomic) BOOL onAccessTokenRefreshFailedCalled;
 @property(nonatomic) BOOL onProfileUpdateCalled;
 @property(nonatomic) BOOL onChromeIdentityServiceWillBeDestroyedCalled;
 @property(nonatomic, assign) ChromeIdentity* identity;
 @property(nonatomic, readonly) NSDictionary* userInfo;
 @property(nonatomic, readonly)
     ios::ChromeIdentityService::Observer* observerBridge;
 @end
 
 @implementation TestChromeIdentityServiceObserver {
-  scoped_ptr<ios::ChromeIdentityService::Observer> observer_bridge_;
+  std::unique_ptr<ios::ChromeIdentityService::Observer> observer_bridge_;
 }
 
 @synthesize onIdentityListChangedCalled = _onIdentityListChangedCalled;
 @synthesize onAccessTokenRefreshFailedCalled =
     _onAccessTokenRefreshFailedCalled;
 @synthesize onProfileUpdateCalled = _onProfileUpdateCalled;
 @synthesize onChromeIdentityServiceWillBeDestroyedCalled =
     _onChromeIdentityServiceWillBeDestroyedCalled;
 @synthesize identity = _identity;
 @synthesize userInfo = _userInfo;
@@ skipping 91 matching lines @@
 // Tests that |onChromeIdentityServiceWillBeDestroyed| is forwarded.
 TEST_F(ChromeIdentityServiceObserverBridgeTest,
        onChromeIdentityServiceWillBeDestroyed) {
   ASSERT_FALSE(GetTestObserver().onChromeIdentityServiceWillBeDestroyedCalled);
   GetObserverBridge()->OnChromeIdentityServiceWillBeDestroyed();
   EXPECT_FALSE(GetTestObserver().onIdentityListChangedCalled);
   EXPECT_FALSE(GetTestObserver().onAccessTokenRefreshFailedCalled);
   EXPECT_FALSE(GetTestObserver().onProfileUpdateCalled);
   EXPECT_TRUE(GetTestObserver().onChromeIdentityServiceWillBeDestroyedCalled);
 }