Adding the basic class outline for modal data partitioning

ActiveStateManager, CRWBrowsingDataStore, BrowsingDataPartition are public
interfaces -- for use outside of web.

ActiveStateManager has a concept of "active" state. At most one ActiveStateManager can
be active at a given time.

ActiveStateManager and BrowsingDataParition have a 1:1 relationship with
BrowserState.

Also renamed browser_state.cc to browser_state.mm

Look at the corresponding bugs for the design doc.

BUG=480654, 480507

Review URL: https://codereview.chromium.org/1138083004

Cr-Commit-Position: refs/heads/master@{#331418}

1 files changed, 58 insertions, 0 deletions

diff --git a/ios/web/active_state_manager_impl.h b/ios/web/active_state_manager_impl.h
new file mode 100644
index 0000000..05efd40
--- /dev/null
+++ b/ios/web/active_state_manager_impl.h
@@ -0,0 +1,58 @@
+// 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.
+
+#ifndef IOS_WEB_ACTIVE_STATE_MANAGER_IMPL_H_
+#define IOS_WEB_ACTIVE_STATE_MANAGER_IMPL_H_
+
+#include "base/macros.h"
+#include "base/observer_list.h"
+#include "base/supports_user_data.h"
+#include "ios/web/public/active_state_manager.h"
+
+namespace web {
+
+class BrowserState;
+
+// Concrete subclass of web::ActiveStateManager. Informs observers when an
+// ActiveStateManager becomes active/inactive.
+class ActiveStateManagerImpl : public ActiveStateManager,
+                               public base::SupportsUserData::Data {
+ public:
+  explicit ActiveStateManagerImpl(BrowserState* browser_state);
+  ~ActiveStateManagerImpl() override;
+
+  // ActiveStateManager methods.
+  void SetActive(bool active) override;
+  bool IsActive() override;
+
+  // Observer that is notified when a ActiveStateManager becomes active,
+  // inactive or destroyed.
+  class Observer {
+   public:
+    // Called when the ActiveStateManager becomes active.
+    virtual void OnActive() = 0;
+    // Called when the ActiveStateManager becomes inactive.
+    virtual void OnInactive() = 0;
+    // Called just before the ActiveStateManager is destroyed.
+    virtual void WillBeDestroyed() = 0;
+  };
+  // Adds an observer for this class. An observer should not be added more
+  // than once. The caller retains the ownership of the observer object.
+  void AddObserver(Observer* obs);
+  // Removes an observer.
+  void RemoveObserver(Observer* obs);
+
+ private:
+  BrowserState* browser_state_;  // weak, owns this object.
+  // true if the ActiveStateManager is active.
+  bool active_;
+  // The list of observers.
+  ObserverList<Observer> observer_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(ActiveStateManagerImpl);
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_ACTIVE_STATE_MANAGER_IMPL_H_