Create FakeProviders for NativeAppMetadata and NativeAppManager

ios/public/provider/chrome/browser/native_app_launcher/fake_native_app_whitelist_manager.h

Index: ios/public/provider/chrome/browser/native_app_launcher/fake_native_app_whitelist_manager.h
diff --git a/ios/public/provider/chrome/browser/native_app_launcher/fake_native_app_whitelist_manager.h b/ios/public/provider/chrome/browser/native_app_launcher/fake_native_app_whitelist_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..cbaaae17c29674087e27a177882649d06e3137c5
--- /dev/null
+++ b/ios/public/provider/chrome/browser/native_app_launcher/fake_native_app_whitelist_manager.h
@@ -0,0 +1,23 @@
+// 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.
+
+#ifndef IOS_PUBLIC_PROVIDER_CHROME_BROWSER_NATIVE_APP_LAUNCHER_FAKE_NATIVE_APP_WHITELIST_MANAGER_H_
+#define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_NATIVE_APP_LAUNCHER_FAKE_NATIVE_APP_WHITELIST_MANAGER_H_
+
+#import <Foundation/Foundation.h>
+
+#import "ios/public/provider/chrome/browser/native_app_launcher/native_app_whitelist_manager.h"
+
+// Fake NativeAppWhitelistManager used for testing purposes.
+@interface FakeNativeAppWhitelistManager : NSObject<NativeAppWhitelistManager>
+
+// Holds the metadata object from initWithMetadata.

[rohitrao (ping after 24h), 2016/11/25 00:34:38]

This comment should mention what metadata is used for.  Maybe something like:

// The metadata returned by calls to |newNativeAppForURL:|.

[sczs1, 2016/11/26 04:10:18]

Done.

+@property(nonatomic, readonly) id<NativeAppMetadata, NSObject> metadata;
+
+// Creates a new manager with |metadata| as a parameter.
+- (instancetype)initWithMetadata:(id<NativeAppMetadata>)metadata;

[rohitrao (ping after 24h), 2016/11/25 00:34:38]

How about removing this initializer and making the property readwrite?  You
could imagine a test wanting to change the returned metadata during the test.

[sczs1, 2016/11/26 04:10:18]

Was thinking the same thing, will change it.

+
+@end
+
+#endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_NATIVE_APP_LAUNCHER_FAKE_NATIVE_APP_WHITELIST_MANAGER_H_