Add the JNI code in order to let Java use the InterestsFetcher.

chrome/browser/android/interests_service.h

Index: chrome/browser/android/interests_service.h
diff --git a/chrome/browser/android/interests_service.h b/chrome/browser/android/interests_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..cf4dd138fcc8c2e85138a3546d76e82ac53d26c8
--- /dev/null
+++ b/chrome/browser/android/interests_service.h
@@ -0,0 +1,42 @@
+// 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 CHROME_BROWSER_ANDROID_INTERESTS_SERVICE_H_

[Bernhard Bauer, 2015/10/07 15:26:37]

Can we move this file to chrome/browser/interests/android/?

+#define CHROME_BROWSER_ANDROID_INTERESTS_SERVICE_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "chrome/browser/interests/interests_fetcher.h"

[Bernhard Bauer, 2015/10/07 15:26:37]

You can forward-declare this and Profile.

OTOH, you might want to explicitly include weak_ptr.h and scoped_ptr.h (because
Include-What-You-Use).

[PEConn, 2015/10/07 18:27:20]

Done. I forward declared Profile and ScopedJavaGlobalRef. I couldn't do that for
InterestsFetcher because we use Interest, its inner class.

+#include "chrome/browser/profiles/profile.h"
+
+// Provides a list of user interests to Java
+class InterestsService {
+ public:
+  explicit InterestsService(Profile* profile);
+  virtual ~InterestsService();
+
+  void Destroy(JNIEnv* env, jobject obj);
+  static bool Register(JNIEnv* env);
+  void GetInterests(JNIEnv* env,
+                    jobject obj,
+                    jobject j_callback);
+
+ private:
+  void OnObtainedInterests(
+      InterestsFetcher* fetcher,
+      const base::android::ScopedJavaGlobalRef<jobject>& j_callback,
+      scoped_ptr<std::vector<InterestsFetcher::Interest>> interests);
+
+  static jobjectArray ConvertInterestsToJava(
+      scoped_ptr<std::vector<InterestsFetcher::Interest>> interests);
+
+  Profile* profile_;
+
+  base::WeakPtrFactory<InterestsService> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(InterestsService);
+};
+
+#endif  // CHROME_BROWSER_ANDROID_INTERESTS_SERVICE_H_