Add BlimpClientContext and factory with real and dummy implementation

chrome/browser/android/blimp/blimp_client_context_factory.h

+// 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 CHROME_BROWSER_ANDROID_BLIMP_BLIMP_CLIENT_CONTEXT_FACTORY_H_
+#define CHROME_BROWSER_ANDROID_BLIMP_BLIMP_CLIENT_CONTEXT_FACTORY_H_
+
+#include "base/macros.h"
+#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
+
+namespace base {
+template <typename T>
+struct DefaultSingletonTraits;
+}  // namespace base
+
+namespace blimp {
+namespace client {
+class BlimpClientContext;
+}  // namespace client
+}  // namespace blimp
+
+namespace content {
+class BrowserContext;
+}  // namespace content
+
+// BlimpClientContextFactory is the main client class for interactive with
+// blimp.
+class BlimpClientContextFactory : public BrowserContextKeyedServiceFactory {
+ public:
+  // Returns singleton instance of BlimpClientContextFactory.
+  static BlimpClientContextFactory* GetInstance();
+
+  // Returns the BlimpClientContext associated with |context|.
+  static blimp::client::BlimpClientContext* GetForBrowserContext(
+      content::BrowserContext* context);
+
+ private:
+  friend struct base::DefaultSingletonTraits<BlimpClientContextFactory>;
+
+  BlimpClientContextFactory();
+  ~BlimpClientContextFactory() override;
+
+  // BrowserContextKeyedServiceFactory overrides:
+  KeyedService* BuildServiceInstanceFor(
+      content::BrowserContext* context) const override;
+  content::BrowserContext* GetBrowserContextToUse(
+      content::BrowserContext* context) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(BlimpClientContextFactory);
+};
+
+#endif  // CHROME_BROWSER_ANDROID_BLIMP_BLIMP_CLIENT_CONTEXT_FACTORY_H_