[sync] Upstream the Android ProfileSyncService

chrome/android/java/src/org/chromium/chrome/browser/identity/SettingsSecureBasedIdentificationGenerator.java

+// Copyright 2013 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.
+
+package org.chromium.chrome.browser.identity;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import com.google.common.annotations.VisibleForTesting;
+
+import org.chromium.chrome.browser.util.HashUtil;
+
+import javax.annotation.Nullable;
+
+/**
+ * Unique identificator implementation that uses the Settings.Secure.ANDROID_ID field and MD5
+ * hashing.
+ */
+public class SettingsSecureBasedIdentificationGenerator implements UniqueIdentificationGenerator {
+    public static final String GENERATOR_ID = "SETTINGS_SECURE_ANDROID_ID";
+    private final Context mContext;
+
+    public SettingsSecureBasedIdentificationGenerator(Context context) {
+        // Since we do not know the lifetime of the given context, we get the application context
+        // to ensure it is always possible to use it.
+        mContext = context.getApplicationContext();
+    }
+
+    @Override
+    public String getUniqueId(@Nullable String salt) {
+        String androidId = getAndroidId();
+        if (androidId == null) {
+            return "";
+        }
+
+        String md5Hash = HashUtil.getMd5Hash(
+                new HashUtil.Params(androidId).withSalt(salt));
+        return md5Hash == null ? "" : md5Hash;
+    }
+
+    @VisibleForTesting
+    String getAndroidId() {
+        return Settings.Secure.getString(mContext.getContentResolver(), Settings.Secure.ANDROID_ID);
+    }
+}