Lazily instantiate LauncherAppState.

The application context for LauncherAppState is supplied by
the application whenever it starts; don't ask for an
instance before that.

Change-Id: I1ca8ea04238a357a682f79250f08813ead7ae532
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index 5253591..d098805 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -167,9 +167,11 @@
         public void onPageBoundSynchronously(int page);
     }
 
-    LauncherModel(Context context, IconCache iconCache) {
+    LauncherModel(LauncherAppState app, IconCache iconCache) {
+        final Context context = app.getContext();
+
         mAppsCanBeOnExternalStorage = !Environment.isExternalStorageEmulated();
-        mApp = LauncherAppState.getInstance();
+        mApp = app;
         mBgAllAppsList = new AllAppsList(iconCache);
         mIconCache = iconCache;
 
@@ -2323,10 +2325,8 @@
                     for (int i=0; i<N; i++) {
                         if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.updatePackage " + packages[i]);
                         mBgAllAppsList.updatePackage(context, packages[i]);
-                        LauncherAppState app =
-                                LauncherAppState.getInstance();
                         WidgetPreviewLoader.removeFromDb(
-                                app.getWidgetPreviewCacheDb(), packages[i]);
+                                mApp.getWidgetPreviewCacheDb(), packages[i]);
                     }
                     break;
                 case OP_REMOVE:
@@ -2334,10 +2334,8 @@
                     for (int i=0; i<N; i++) {
                         if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.removePackage " + packages[i]);
                         mBgAllAppsList.removePackage(packages[i]);
-                        LauncherAppState app =
-                                LauncherAppState.getInstance();
                         WidgetPreviewLoader.removeFromDb(
-                                app.getWidgetPreviewCacheDb(), packages[i]);
+                                mApp.getWidgetPreviewCacheDb(), packages[i]);
                     }
                     break;
             }