Refactor ActionBarController and tests

The original CL to fix ActionBarControllerTest by using an
ActivityInstrumentationTestCase was too heavyweight and caused flaky
test. It was also indicative of a flaw in the original design that
ActionBar couldn't be mocked out easily.

Refactor the code so that:
1) getActionBar() is no longer needed
2) Respect the invariant that all access to the actionBar goes through the
ActionBarController (see the changes in ListsFragment) so that any change to
the ActionBar's hide offset can be tracked appropriately.

Bug: 17487016
Change-Id: I935b683ddb301ca5d3952889af1381bdbdcc97d3
diff --git a/src/com/android/dialer/DialtactsActivity.java b/src/com/android/dialer/DialtactsActivity.java
index aacf208..1c93350 100644
--- a/src/com/android/dialer/DialtactsActivity.java
+++ b/src/com/android/dialer/DialtactsActivity.java
@@ -1134,6 +1134,11 @@
         return mActionBarController.isActionBarShowing();
     }
 
+    @Override
+    public ActionBarController getActionBarController() {
+        return mActionBarController;
+    }
+
     public boolean isDialpadShown() {
         return mIsDialpadShown;
     }
@@ -1144,13 +1149,13 @@
     }
 
     @Override
-    public int getActionBarHeight() {
-        return mActionBarHeight;
+    public void setActionBarHideOffset(int offset) {
+        getActionBar().setHideOffset(offset);
     }
 
     @Override
-    public void setActionBarHideOffset(int hideOffset) {
-        mActionBarController.setHideOffset(hideOffset);
+    public int getActionBarHeight() {
+        return mActionBarHeight;
     }
 
     /**