Added permission check for GET_ACCOUNTS.

This ensures that when the GET_ACCOUNTS permission is not available,
Chrome does not crash, but instead returns no accounts.

- Ensures that the IntentHelper goes through the AccountManagerHelper
- The ChildAccountService now observes the AccountChangedReceiver
  (which forwards the braodcast) instead of listening directly to the
  AccountManager.
- When the GET_ACCOUNTS permission is not available, the
  ChildAccountService always assumes the accounts is not a child
  account.

BUG=509826

Review URL: https://codereview.chromium.org/1232573004

Cr-Commit-Position: refs/heads/master@{#338609}

2 files changed, 26 insertions, 2 deletions

diff --git a/sync/android/java/src/org/chromium/sync/signin/AccountManagerHelper.java b/sync/android/java/src/org/chromium/sync/signin/AccountManagerHelper.java
index 941e974..30ce9ee 100644
--- a/sync/android/java/src/org/chromium/sync/signin/AccountManagerHelper.java
+++ b/sync/android/java/src/org/chromium/sync/signin/AccountManagerHelper.java
@@ -5,6 +5,7 @@
 package org.chromium.sync.signin;
 
 
+import android.Manifest;
 import android.accounts.Account;
 import android.accounts.AccountManager;
 import android.accounts.AccountManagerCallback;
@@ -133,7 +134,22 @@ public class AccountManagerHelper {
         return accountNames;
     }
 
+    /**
+     * Returns all accounts on the device, including non-Google accounts. Unless it is really
+     * necessary to get absolutely all accounts on the device, use {@link #getGoogleAccounts}.
+     * @return an array of accounts.
+     */
+    public Account[] getAccounts() {
+        if (!hasGetAccountsPermission()) return new Account[]{};
+        return mAccountManager.getAccounts();
+    }
+
+    /**
+     * Returns all Google accounts on the device.
+     * @return an array of accounts.
+     */
     public Account[] getGoogleAccounts() {
+        if (!hasGetAccountsPermission()) return new Account[]{};
         return mAccountManager.getAccountsByType(GOOGLE_ACCOUNT_TYPE);
     }
 
@@ -261,7 +277,12 @@ public class AccountManagerHelper {
     private boolean hasUseCredentialsPermission() {
         return BuildInfo.isMncOrLater()
                 || mApplicationContext.checkPermission("android.permission.USE_CREDENTIALS",
-                        Process.myPid(), Process.myUid()) == PackageManager.PERMISSION_GRANTED;
+                Process.myPid(), Process.myUid()) == PackageManager.PERMISSION_GRANTED;
+    }
+
+    public boolean hasGetAccountsPermission() {
+        return mApplicationContext.checkPermission(Manifest.permission.GET_ACCOUNTS,
+                Process.myPid(), Process.myUid()) == PackageManager.PERMISSION_GRANTED;
     }
 
     // Gets the auth token synchronously
diff --git a/sync/android/javatests/src/org/chromium/sync/notifier/signin/AccountManagerHelperTest.java b/sync/android/javatests/src/org/chromium/sync/notifier/signin/AccountManagerHelperTest.java
index 8633fef..90e1522 100644
--- a/sync/android/javatests/src/org/chromium/sync/notifier/signin/AccountManagerHelperTest.java
+++ b/sync/android/javatests/src/org/chromium/sync/notifier/signin/AccountManagerHelperTest.java
@@ -13,6 +13,9 @@ import org.chromium.sync.signin.AccountManagerHelper;
 import org.chromium.sync.test.util.AccountHolder;
 import org.chromium.sync.test.util.MockAccountManager;
 
+/**
+ * Test class for {@link AccountManagerHelper}.
+ */
 public class AccountManagerHelperTest extends InstrumentationTestCase {
 
     private MockAccountManager mAccountManager;
@@ -22,7 +25,7 @@ public class AccountManagerHelperTest extends InstrumentationTestCase {
     protected void setUp() throws Exception {
         super.setUp();
 
-        Context context = getInstrumentation().getContext();
+        Context context = getInstrumentation().getTargetContext();
         mAccountManager = new MockAccountManager(context, context);
         AccountManagerHelper.overrideAccountManagerHelperForTests(context, mAccountManager);
         mHelper = AccountManagerHelper.get(context);