Refactoring all apps search to support external search bar.

- Adding support for an external search bar that can be used
  to search a container view.  This adds a new interface
  AllAppsSearchController which manages the external search
  bar.  Each controller will have its own search implementation
  which means that we no longer need a common AppSearchManager
  interface.
- Removing elevation controller as we no longer have a builtin
  search bar in all apps
- Refactoring container view insets so that they behave
  the same in all containers.
- Refactoring apps view to ensure that we only update the number
  of columns with the available width
- Cleaning up LauncherCallbacks interface

Bug: 20127840
Bug: 21494973

Change-Id: I710b8e18196961d77d8a29f0c345531d480936fe

src/com/android/launcher3/Workspace.java

@@ -1998,10 +1998,10 @@ public class Workspace extends PagedView
      * to that new state.
      */
     public Animator setStateWithAnimation(State toState, int toPage, boolean animated,
-                                          HashMap<View, Integer> layerViews) {
+            boolean hasOverlaySearchBar, HashMap<View, Integer> layerViews) {
         // Create the animation to the new state
         Animator workspaceAnim =  mStateTransitionAnimation.getAnimationToState(getState(),
-                toState, toPage, animated, layerViews);
+                toState, toPage, animated, hasOverlaySearchBar, layerViews);
 
         // Update the current state
         mState = toState;
@@ -2100,11 +2100,6 @@ public class Workspace extends PagedView
         }
     }
 
-    @Override
-    public View getContent() {
-        return this;
-    }
-
     /**
      * Returns the drawable for the given text view.
      */