Keyboard Lock Host implementation

components/keyboard_lock/key_hook_activator_collection.h

Index: components/keyboard_lock/key_hook_activator_collection.h
diff --git a/components/keyboard_lock/key_hook_activator_collection.h b/components/keyboard_lock/key_hook_activator_collection.h
new file mode 100644
index 0000000000000000000000000000000000000000..c33ecd2c97555605fbd5727f514b7cd74d428ff5
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+++ b/components/keyboard_lock/key_hook_activator_collection.h
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+// Copyright 2017 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 COMPONENTS_KEYBOARD_LOCK_KEY_HOOK_ACTIVATOR_COLLECTION_H_
+#define COMPONENTS_KEYBOARD_LOCK_KEY_HOOK_ACTIVATOR_COLLECTION_H_
+
+#include <map>
+#include <memory>
+
+#include "base/threading/thread_checker.h"
+#include "components/keyboard_lock/key_hook_activator.h"
+
+namespace content {
+class WebContents;
+}  // namespace content
+
+namespace keyboard_lock {
+
+class KeyHookActivator;
+
+// A collection of KeyHookActivator instances.
+// All the public functions can only be called in one thread.
+class KeyHookActivatorCollection final {
+ public:
+  KeyHookActivatorCollection();
+  ~KeyHookActivatorCollection();
+
+  // Returning a nullptr if no KeyHookActivator has been registered for
+  // |contents|.
+  KeyHookActivator* Find(const content::WebContents* contents) const;
+
+  void Insert(const content::WebContents* contents,
+              std::unique_ptr<KeyHookActivator> key_hook);
+
+  // Do nothing if |contents| is not found in the collection: web page may call
+  // cancelKeyboardLock() without calling requestKeyboardLock() before.
+  void Erase(const content::WebContents* contents);
+
+ private:
+  // GUARDED_BY(thread_checker_)
+  std::map<const content::WebContents*, std::unique_ptr<KeyHookActivator>>
+      activators_;
+
+  // Ensures |activators_| is only accessed in |runner_| thread.
+  base::ThreadChecker thread_checker_;
+};
+
+}  // namespace keyboard_lock
+
+#endif  // COMPONENTS_KEYBOARD_LOCK_KEY_HOOK_ACTIVATOR_COLLECTION_H_