Windows docking should get triggered by pressing against the screen edge

ash/wm/window_util.cc

Index: ash/wm/window_util.cc
diff --git a/ash/wm/window_util.cc b/ash/wm/window_util.cc
index 3f0f23422ce0a5417c6070fc2ea71463e9bbe78d..19028b848dd352686a07f6ca991eeb037a3391ad 100644
--- a/ash/wm/window_util.cc
+++ b/ash/wm/window_util.cc
@@ -77,6 +77,8 @@ bool CanResizeWindow(const aura::Window* window) {
 bool CanSnapWindow(aura::Window* window) {
   if (!CanResizeWindow(window))
     return false;
+  if (window->type() == aura::client::WINDOW_TYPE_PANEL)
+    return false;
   // If a window has a maximum size defined, snapping may make it too big.
   return window->delegate() ? window->delegate()->GetMaximumSize().IsEmpty() :
                               true;