Disable left/right/maximize for panels.

ash/wm/workspace/frame_maximize_button.cc

Index: ash/wm/workspace/frame_maximize_button.cc
diff --git a/ash/wm/workspace/frame_maximize_button.cc b/ash/wm/workspace/frame_maximize_button.cc
index 989b288cb3ba2a22a0ee6bbb9fa28ecbbaa717e5..bbc5c250948db2a5701a337a41d178454d4e5a6b 100644
--- a/ash/wm/workspace/frame_maximize_button.cc
+++ b/ash/wm/workspace/frame_maximize_button.cc
@@ -96,6 +96,8 @@ FrameMaximizeButton::FrameMaximizeButton(views::ButtonListener* listener,
     : ImageButton(listener),
       frame_(frame),
       is_snap_enabled_(false),
+      is_left_right_enabled_(true),
+      is_maximize_enabled_(true),
       exceeded_drag_threshold_(false),
       snap_type_(SNAP_NONE) {
   // TODO(sky): nuke this. It's temporary while we don't have good images.
@@ -235,6 +237,10 @@ void FrameMaximizeButton::UpdateSnap(const gfx::Point& location) {
     }
     return;
   }
+  if ((!is_left_right_enabled_ && (type == SNAP_LEFT || type == SNAP_RIGHT)) ||

[sky, 2012/03/25 22:53:05]

Move this to SnapTypeForLocation, otherwise we're going to get inconsistent
behavior. Also, you'll need to update the tooltip too.

[stevenjb, 2012/03/25 23:11:37]

Done. 

+      (!is_maximize_enabled_ && type == SNAP_MAXIMIZE)) {
+    return;
+  }
 
   snap_type_ = type;
   snap_sizer_.reset();