Fix Harmony popover buttons being flush with their content.

ui/views/bubble/bubble_dialog_delegate.cc

 // Copyright 2016 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/bubble/bubble_dialog_delegate.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "build/build_config.h"
 #include "ui/accessibility/ax_node_data.h"
@@ skipping 80 matching lines @@
 BubbleDialogDelegateView* BubbleDialogDelegateView::AsBubbleDialogDelegate() {
   return this;
 }
 
 bool BubbleDialogDelegateView::ShouldShowCloseButton() const {
   return false;
 }
 
 ClientView* BubbleDialogDelegateView::CreateClientView(Widget* widget) {
   DialogClientView* client = new DialogClientView(widget, GetContentsView());
-  client->SetButtonRowInsets(gfx::Insets());
+  LayoutProvider* provider = LayoutProvider::Get();
+  // The other three sides are taken care of by the |margins_| given to
+  // BubbleFrameView in CreateNonClientFrameView().
+  client->SetButtonRowInsets(gfx::Insets(
+      provider->GetDistanceMetric(DISTANCE_BUBBLE_BUTTON_TOP_MARGIN), 0, 0, 0));
   widget->non_client_view()->set_mirror_client_in_rtl(mirror_arrow_in_rtl_);
   return client;
 }
 
 NonClientFrameView* BubbleDialogDelegateView::CreateNonClientFrameView(
     Widget* widget) {
   BubbleFrameView* frame = new BubbleFrameView(title_margins_, margins_);
   // Note: In CreateBubble, the call to SizeToContents() will cause
   // the relayout that this call requires.
   frame->SetTitleFontList(GetTitleFontList());
@@ skipping 205 matching lines @@
   // http://crbug.com/474622 for details.
   if (widget == GetWidget() && visible) {
     ui::AXNodeData node_data;
     GetAccessibleNodeData(&node_data);
     if (node_data.role == ui::AX_ROLE_ALERT_DIALOG)
       NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);
   }
 }
 
 }  // namespace views