Introduce ChromeBrowserState interface

The ChromeBrowserState interface will serve as iOS's alternative to
Profile.

BUG=436897

Review URL: https://codereview.chromium.org/748853005

Cr-Commit-Position: refs/heads/master@{#306357}

ios/ios.gyp

@@ -12,6 +12,7 @@
       'dependencies': [
         'ios_base.gyp:*',
         'ios_tests_unit.gyp:*',
+        'provider/ios_provider_chrome.gyp:*',
         'provider/ios_provider_web.gyp:*',
         'web/ios_web.gyp:*',
       ],

ios/provider/ios_provider_chrome.gyp

@@ -0,0 +1,22 @@
+# Copyright 2013 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.
+{
+  'variables': {
+    'chromium_code': 1,
+   },
+  'targets': [
+    {
+      'target_name': 'ios_provider_chrome_browser',
+      'type': 'static_library',
+      'sources': [
+        '../public/provider/chrome/browser/browser_state/chrome_browser_state.cc',
+        '../public/provider/chrome/browser/browser_state/chrome_browser_state.h',
+      ],
+      'dependencies': [
+        '../../base/base.gyp:base',
+        'ios_provider_web.gyp:ios_provider_web',
+      ],
+    },
+  ],
+}

ios/public/provider/chrome/browser/DEPS

@@ -0,0 +1,3 @@
+include_rules = [
+  "+ios/public/provider/web",
+]

ios/public/provider/chrome/browser/browser_state/chrome_browser_state.cc

@@ -0,0 +1,18 @@
+// 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 "ios/public/provider/chrome/browser/browser_state/chrome_browser_state.h"
+
+#include "ios/public/provider/web/web_state.h"
+
+namespace ios {
+
+// static
+ChromeBrowserState* ChromeBrowserState::FromBrowserState(
+    web::BrowserState* browser_state) {
+  // This is safe; this is the only implementation of BrowserState.
+  return static_cast<ChromeBrowserState*>(browser_state);
+}
+
+}  // namespace ios

ios/public/provider/chrome/browser/browser_state/chrome_browser_state.h

@@ -0,0 +1,50 @@
+// Copyright 2013 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_BROWSER_STATE_CHROME_BROWSER_STATE_H_
+#define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_BROWSER_STATE_CHROME_BROWSER_STATE_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ios/web/public/browser_state.h"
+
+class PrefService;
+
+namespace ios {
+
+// This class is a Chrome-specific extension of the BrowserState interface.
+class ChromeBrowserState : public web::BrowserState {
+ public:
+  ~ChromeBrowserState() override {}
+
+  // Returns the ChromeBrowserState corresponding to the given BrowserState.
+  static ChromeBrowserState* FromBrowserState(BrowserState* browser_state);
+
+  // Returns the original "recording" ChromeBrowserState. This method returns
+  // |this| if the ChromeBrowserState is not incognito.
+  virtual ChromeBrowserState* GetOriginalChromeBrowserState() = 0;
+
+  // Returns the incognito version of this ChromeBrowserState. The returned
+  // ChromeBrowserState instance is owned by this ChromeBrowserState instance.
+  // WARNING: This will create the OffTheRecord ChromeBrowserState if it
+  // doesn't already exist.
+  virtual ChromeBrowserState* GetOffTheRecordChromeBrowserState() = 0;
+
+  // Destroys the OffTheRecord ChromeBrowserState that is associated with this
+  // ChromeBrowserState, if one exists.
+  virtual void DestroyOffTheRecordChromeBrowserState() = 0;
+
+  // Retrieves a pointer to the PrefService that manages the preferences.
+  virtual PrefService* GetPrefs() = 0;
+
+ protected:
+  ChromeBrowserState() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserState);
+};
+
+}  // namespace ios
+
+#endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_BROWSER_STATE_CHROME_BROWSER_STATE_H_