save "retain loader" state DO NOT MERGE

We cannot pull the "retain loader" state from the Activity; an Activity may
not always be hosting a Fragment. Instead, save the "retain loader" state
inside the individual fragments.

Bug: 23838271
Change-Id: I8358183a7689b5a571ea7be03d769186b2812600
(cherry picked from commit c5ac16f531)

core/java/android/app/Fragment.java

@@ -460,6 +460,9 @@ public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListene
     // If set this fragment is being retained across the current config change.
     boolean mRetaining;
 
+    // If set this fragment's loaders are being retained across the current config change.
+    boolean mRetainLoader;
+
     // If set this fragment has menu items to contribute.
     boolean mHasMenu;
 
@@ -2401,7 +2404,7 @@ public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListene
                 mLoaderManager = mHost.getLoaderManager(mWho, mLoadersStarted, false);
             }
             if (mLoaderManager != null) {
-                if (mRetaining) {
+                if (mRetainLoader) {
                     mLoaderManager.doRetain();
                 } else {
                     mLoaderManager.doStop();

core/java/android/app/FragmentController.java

@@ -341,6 +341,7 @@ public class FragmentController {
      */
     public void doLoaderStop(boolean retain) {
         mHost.doLoaderStop(retain);
+        mHost.mFragmentManager.setRetainLoader(retain);
     }
 
     /**

core/java/android/app/FragmentManager.java

@@ -869,6 +869,17 @@ final class FragmentManagerImpl extends FragmentManager implements LayoutInflate
         }
     }
 
+    void setRetainLoader(boolean retain) {
+        if (mActive != null) {
+            for (int i=0; i<mActive.size(); i++) {
+                Fragment f = mActive.get(i);
+                if (f != null) {
+                    f.mRetainLoader = retain;
+                }
+            }
+        }
+    }
+
     void moveToState(Fragment f, int newState, int transit, int transitionStyle,
             boolean keepActive) {
         if (DEBUG && false) Log.v(TAG, "moveToState: " + f