Fix bug 3105695 - Action modes in dialogs or other small windows

Overlay action modes now show in their own windows aligned to the top
of the screen.

Change-Id: I81600bbd1bcaeb59fdcf0a959bd35f82165baa2c

core/java/com/android/internal/view/StandaloneActionMode.java

@@ -87,7 +87,6 @@ public class StandaloneActionMode extends ActionMode implements MenuBuilder.Call
         mFinished = true;
 
         mCallback.onDestroyActionMode(this);
-        mContextView.setVisibility(View.GONE);
     }
 
     @Override

core/java/com/android/internal/widget/ActionBarContextView.java

@@ -213,7 +213,7 @@ public class ActionBarContextView extends ViewGroup {
         }
 
         final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
-        if (heightMode != MeasureSpec.AT_MOST) {
+        if (heightMode == MeasureSpec.UNSPECIFIED) {
             throw new IllegalStateException(getClass().getSimpleName() + " can only be used " +
                     "with android:layout_height=\"wrap_content\"");
         }