Enable Chrome to tweak search engines for some locales

chrome/android/java/src/org/chromium/chrome/browser/locale/SpecialLocaleHandler.java

+// 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.
+
+package org.chromium.chrome.browser.locale;
+
+/**
+ * A Handler for changes in a given special locale. This is a JNI bridge and it owns the native
+ * object. Make sure to call Destroy() after this object is not used anymore.
+ */
+public class SpecialLocaleHandler {
+    private final String mLocaleId;
+    private long mNativeSpecialLocaleHandler;
+    private boolean mAddedToService;
+
+    /**
+     * Creates a {@link SpecialLocaleHandler} that handles changes for the given locale.
+     * @param localeId Country id of the locale. Should be 2 characters long.
+     */
+    public SpecialLocaleHandler(String localeId) {
+        assert localeId.length() == 2;
+        mLocaleId = localeId;
+        mNativeSpecialLocaleHandler = nativeInit(localeId);
+    }
+
+    /**
+     * This *must* be called after the {@link SpecialLocaleHandler} is not used anymore.
+     */
+    public void destroy() {
+        assert mNativeSpecialLocaleHandler != 0;
+        nativeDestroy(mNativeSpecialLocaleHandler);
+        mNativeSpecialLocaleHandler = 0;
+    }
+
+    /**
+     * Loads the template urls for this locale, and adds it to template url service. If the device
+     * was initialized in the given special locale, no-op here.
+     * @return Whether loading is needed.
+     */
+    public boolean loadTemplateUrls() {
+        assert mNativeSpecialLocaleHandler != 0;
+        // If the locale is the same as the one set at install time, there is no need to load the
+        // search engines, as they are already cached in the template url service.
+        mAddedToService = nativeLoadTemplateUrls(mNativeSpecialLocaleHandler);
+        return mAddedToService;
+    }
+
+    /**
+     * Removes the template urls that was added by {@link #loadTemplateUrls()}. No-op if
+     * {@link #loadTemplateUrls()} returned false.
+     */
+    public void removeTemplateUrls() {
+        assert mNativeSpecialLocaleHandler != 0;
+        if (mAddedToService) nativeRemoveTemplateUrls(mNativeSpecialLocaleHandler);
+    }
+
+    /**
+     * Overrides the default search provider in special locale.
+     */
+    public void overrideDefaultSearchProvider() {
+        assert mNativeSpecialLocaleHandler != 0;
+        nativeOverrideDefaultSearchProvider(mNativeSpecialLocaleHandler);
+    }
+
+    private static native long nativeInit(String localeId);
+    private static native void nativeDestroy(long nativeSpecialLocaleHandler);
+    private static native boolean nativeLoadTemplateUrls(long nativeSpecialLocaleHandler);
+    private static native void nativeRemoveTemplateUrls(long nativeSpecialLocaleHandler);
+    private static native void nativeOverrideDefaultSearchProvider(long nativeSpecialLocaleHandler);
+}