Attempt 2: Allows tab dragging when maximized on aura. To fix it I made it so

ash/wm/workspace/workspace_window_resizer.h

Index: ash/wm/workspace/workspace_window_resizer.h
diff --git a/ash/wm/workspace/workspace_window_resizer.h b/ash/wm/workspace/workspace_window_resizer.h
index d32b0be1e5571b39f67fc2f6e07fe580716e1cbd..5c199294eeea26be4ed22e38f716d86be98d6351 100644
--- a/ash/wm/workspace/workspace_window_resizer.h
+++ b/ash/wm/workspace/workspace_window_resizer.h
@@ -43,6 +43,9 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   // Returns true if the window touches the bottom of the work area.
   bool WindowTouchesBottomOfScreen() const;
 
+  // True if the window size (height) should be constrained.
+  const bool constrain_size_;
+
   DISALLOW_COPY_AND_ASSIGN(WorkspaceWindowResizer);
 };