Prevents windows that cannot snap from snapping using a keyboard accelerator

ash/accelerators/accelerator_controller.cc

Index: ash/accelerators/accelerator_controller.cc
diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index ed574b250a8e23cf7a695762e12093bc06073122..7bb9643fbaf7aba62b4262a53b6a566bbf51d17f 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -509,7 +509,8 @@ bool HandleWindowSnap(int action) {
   // http://crbug.com/135487.
   if (!window_state ||
       window_state->window()->type() != ui::wm::WINDOW_TYPE_NORMAL ||
-      window_state->IsFullscreen()) {
+      window_state->IsFullscreen() ||
+      !window_state->CanSnap()) {
     return false;
   }