[MacViews] Show combobox menu popup at mouse press

ui/views/controls/combobox/combobox.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.

[tapted, 2016/06/29 12:02:55]

cl description nit: wordwrap at <80 chars

[spqchan, 2016/06/29 18:29:14]

Done.

 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/combobox/combobox.h"
 
 #include <stddef.h>
 
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 91 matching lines @@
   return bounds;
 }
 
 // The transparent button which holds a button state but is not rendered.
 class TransparentButton : public CustomButton {
  public:
   TransparentButton(ButtonListener* listener)
       : CustomButton(listener) {
     SetAnimationDuration(LabelButton::kHoverAnimationDurationMs);
     SetFocusBehavior(FocusBehavior::NEVER);
+    set_notify_action(PlatformStyle::kMenuActivationAction);
   }
   ~TransparentButton() override {}
 
+#if defined(OS_MACOSX)
+  // Override OnMousePressed() to transfer focus on the parent() on a click

[tapted, 2016/06/29 12:02:55]

"on the parent() on a click" -> "to the parent() on a click."
"on Mac," -> "Except on Mac,"

[spqchan, 2016/06/29 18:29:14]

Done.

+  // on Mac, which doesn't transfer focus when buttons are clicked.
   bool OnMousePressed(const ui::MouseEvent& mouse_event) override {
     parent()->RequestFocus();
+    CustomButton::OnMousePressed(mouse_event);

[tapted, 2016/06/29 12:02:55]

nit: remove this bit (although I think it's fine, there's no longer a reason to
make this change and there could be something subtle).

[spqchan, 2016/06/29 18:29:14]

We need this actually because CustomButton::MousePressed calls NotifyClick()

[tapted, 2016/06/29 23:24:43]

Ah! So, I think we can remove this once the #ifdef is inverted :).

     return true;
   }
+#endif
 
   double GetAnimationValue() const {
     return hover_animation().GetCurrentValue();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TransparentButton);
 };
 
 // Returns the next or previous valid index (depending on |increment|'s value).
@@ skipping 764 matching lines @@
 }
 
 int Combobox::GetArrowContainerWidth() const {
   int padding = style_ == STYLE_NORMAL
                     ? PlatformStyle::kComboboxNormalArrowPadding * 2
                     : kActionLeftPadding + kActionRightPadding;
   return ArrowSize().width() + padding;
 }
 
 }  // namespace views