Implement Android key/value backup

chrome/browser/android/chrome_backup_watcher.cc

Index: chrome/browser/android/chrome_backup_watcher.cc
diff --git a/chrome/browser/android/chrome_backup_watcher.cc b/chrome/browser/android/chrome_backup_watcher.cc
new file mode 100644
index 0000000000000000000000000000000000000000..321b137e559bd501db31fc530c4fb2408d114de2
--- /dev/null
+++ b/chrome/browser/android/chrome_backup_watcher.cc
@@ -0,0 +1,36 @@
+// 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.
+
+#include "chrome/browser/android/chrome_backup_agent.h"
+#include "chrome/browser/android/chrome_backup_watcher.h"
+#include "chrome/browser/profiles/profile.h"
+#include "jni/ChromeBackupWatcher_jni.h"
+
+namespace chrome {
+namespace android {
+
+namespace {
+
+void BackupPrefsChanged(
+    const base::android::ScopedJavaGlobalRef<jobject>& java_watcher) {
+  Java_ChromeBackupWatcher_onBackupPrefsChanged(
+      base::android::AttachCurrentThread(), java_watcher);
+}

[Bernhard Bauer, 2016/11/14 10:05:39]

Add an empty line after this one.

[aberent, 2016/11/14 17:23:40]

Done.

+}
+
+ChromeBackupWatcher::ChromeBackupWatcher(Profile* profile)
+    : registrar_(new PrefChangeRegistrar) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  // Create the Java class, and start watching the Android (Java) preferences
+  java_watcher_.Reset(Java_ChromeBackupWatcher_createChromeBackupWatcher(env));
+  // Now watch the Chrome C++ preferences
+  registrar_->Init(profile->GetPrefs());
+  base::Closure callback = base::Bind(&BackupPrefsChanged, java_watcher_);

[Bernhard Bauer, 2016/11/14 10:05:39]

In the interest of future-proofing the code, use a base::RepeatingClosure (with
base::BindRepeating) here?

[aberent, 2016/11/14 17:23:40]

Done.

+  for (const std::string pref_name : GetBackupPrefNames()) {
+    registrar_->Add(pref_name, callback);
+  }
+}
+
+}  //  namespace android
+}  //  namespace chrome