Add an activity that allows whitelisted applications to clear all data in Chrome.

chrome/android/java/src/org/chromium/chrome/browser/childaccounts/ResetDataActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/childaccounts/ResetDataActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/childaccounts/ResetDataActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/childaccounts/ResetDataActivity.java
new file mode 100644
index 0000000000000000000000000000000000000000..09aa3427e95f2622b8ba7d45c1dbe2138f21e43f
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/childaccounts/ResetDataActivity.java
@@ -0,0 +1,117 @@
+// 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.
+
+package org.chromium.chrome.browser.childaccounts;
+
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.app.ActivityManager;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Build;
+import android.os.Bundle;
+
+import org.chromium.chrome.browser.externalauth.ExternalAuthUtils;
+import org.chromium.chrome.browser.firstrun.FirstRunStatus;
+import org.chromium.chrome.browser.util.IntentUtils;
+
+/**
+ * An activity that allows whitelisted applications to reset all data in Chrome,
+ * as part of the child account setup.
+ */
+public class ResetDataActivity extends Activity  {
+
+    /**
+     * The operation succeeded. Note that this value will only be returned for dry runs, because
+     * sucessfully resetting data will kill this process and return
+     * {@link Activity#RESULT_CANCELED}.
+     */
+    private static final int RESULT_OK = Activity.RESULT_OK;
+
+    /**
+     * The calling activity is not authorized. This activity is only available to Google-signed
+     * applications.
+     */
+    private static final int RESULT_ERROR_UNAUTHORIZED = Activity.RESULT_FIRST_USER;
+
+    /**
+     * Resetting data is not supported.
+     */
+    private static final int RESULT_ERROR_NOT_SUPPORTED = Activity.RESULT_FIRST_USER + 1;
+
+    /**
+     * There was an error resetting data.
+     */
+    private static final int RESULT_ERROR_COULD_NOT_RESET_DATA = Activity.RESULT_FIRST_USER + 2;
+
+    /**
+     * If this is set to true, perform a "dry run", i.e. only check whether there is data to be
+     * cleared. This defaults to true, to avoid accidentally resetting data.
+     */
+    private static final String EXTRA_DRY_RUN = "dry_run";
+
+    /**
+     * If a dry run is performed, this key contains a boolean flag that states whether there is data
+     * to be cleared.
+     */
+    private static final String EXTRA_HAS_DATA = "has_data";
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        if (!authenticateSender()) {
+            returnResult(RESULT_ERROR_UNAUTHORIZED);
+            return;
+        }
+
+        // If resetting data is not supported, immediately return an error.
+        if (!supportsResetData()) {
+            returnResult(RESULT_ERROR_NOT_SUPPORTED);
+            return;
+        }
+
+        boolean dryRun = IntentUtils.safeGetBooleanExtra(getIntent(), EXTRA_DRY_RUN, true);
+
+        if (dryRun) {
+            returnHasData(FirstRunStatus.getFirstRunFlowComplete(this));
+            return;
+        }
+
+        boolean success = resetData();
+
+        // We should only land here if resetting data was not successful, as otherwise the process
+        // will be killed.
+        assert !success;
+        returnResult(RESULT_ERROR_COULD_NOT_RESET_DATA);
+    }
+
+    private boolean authenticateSender() {
+        return ExternalAuthUtils.getInstance().isGoogleSigned(getPackageManager(),
+                getCallingPackage());
+    }
+
+    private boolean supportsResetData() {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
+    }
+
+    @TargetApi(Build.VERSION_CODES.KITKAT)
+    private boolean resetData() {
+        assert supportsResetData();
+        ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
+        return am.clearApplicationUserData();
+    }
+
+    private void returnHasData(boolean hasData) {
+        Intent result = new Intent();
+        result.putExtra(EXTRA_HAS_DATA, hasData);
+        setResult(RESULT_OK, result);
+        finish();
+    }
+
+    private void returnResult(int resultCode) {
+        setResult(resultCode);
+        finish();
+    }
+}