In dialogs & dialog-like bubbles, make the escape button just close the prompt.

ui/views/window/dialog_client_view.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/window/dialog_client_view.h"
 
 #include <algorithm>
 
 #include "build/build_config.h"
 #include "ui/events/keycodes/keyboard_codes.h"
@@ skipping 195 matching lines @@
   // Layout the contents view to the top and side edges of the contents bounds.
   // NOTE: The local insets do not apply to the contents view sides or top.
   const gfx::Rect contents_bounds = GetContentsBounds();
   contents_view()->SetBounds(contents_bounds.x(), contents_bounds.y(),
       contents_bounds.width(), bounds.bottom() - contents_bounds.y());
 }
 
 bool DialogClientView::AcceleratorPressed(const ui::Accelerator& accelerator) {
   DCHECK_EQ(accelerator.key_code(), ui::VKEY_ESCAPE);
 
-  // If there's a cancel button, it handles escape.
-  if (cancel_button_)
-    return cancel_button_->AcceleratorPressed(accelerator);
-
   GetWidget()->Close();
   return true;
 }
 
 void DialogClientView::ViewHierarchyChanged(
     const ViewHierarchyChangedDetails& details) {
   ClientView::ViewHierarchyChanged(details);
   if (details.is_add && details.child == this) {
     UpdateDialogButtons();
     CreateExtraView();
@@ skipping 123 matching lines @@
       std::remove(child_views.begin(), child_views.end(), nullptr),
       child_views.end());
 
   // Setup focus by reordering views. It is not safe to use SetNextFocusableView
   // since child views may be added externally to this view.
   for (size_t i = 0; i < child_views.size(); i++)
     ReorderChildView(child_views[i], i);
 }
 
 }  // namespace views