Making observer registration customizable.

There is a need to skip registering the observer
or register a different observer in cases when
we have an extremely chatty content provider
(think MediaStore).

Change-Id: Iadfb8e0193736cb231762a147c2df1491ad22e0e

api/current.xml

@@ -46584,6 +46584,21 @@
 <parameter name="cursor" type="android.database.Cursor">
 </parameter>
 </method>
+<method name="registerContentObserver"
+ return="void"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="cursor" type="android.database.Cursor">
+</parameter>
+<parameter name="observer" type="android.database.ContentObserver">
+</parameter>
+</method>
 <method name="setProjection"
  return="void"
  abstract="false"

core/java/android/content/CursorLoader.java

@@ -16,6 +16,7 @@
 
 package android.content;
 
+import android.database.ContentObserver;
 import android.database.Cursor;
 import android.net.Uri;
 
@@ -37,14 +38,22 @@ public class CursorLoader extends AsyncTaskLoader<Cursor> {
     public Cursor loadInBackground() {
         Cursor cursor = getContext().getContentResolver().query(mUri, mProjection, mSelection,
                 mSelectionArgs, mSortOrder);
-        // Ensure the cursor window is filled
         if (cursor != null) {
+            // Ensure the cursor window is filled
             cursor.getCount();
-            cursor.registerContentObserver(mObserver);
+            registerContentObserver(cursor, mObserver);
         }
         return cursor;
     }
 
+    /**
+     * Registers an observer to get notifications from the content provider
+     * when the cursor needs to be refreshed.
+     */
+    public void registerContentObserver(Cursor cursor, ContentObserver observer) {
+        cursor.registerContentObserver(mObserver);
+    }
+
     /* Runs on the UI thread */
     @Override
     public void deliverResult(Cursor cursor) {