Fix IME tray bubble (and other tray bubble views).

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 "build/build_config.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 280 matching lines @@
   return view ? static_cast<BubbleFrameView*>(view->frame_view()) : NULL;
 }
 
 void BubbleDialogDelegateView::UpdateColorsFromTheme(
     const ui::NativeTheme* theme) {
   if (!color_explicitly_set_)
     color_ = theme->GetSystemColor(ui::NativeTheme::kColorId_BubbleBackground);
   BubbleFrameView* frame_view = GetBubbleFrameView();
   if (frame_view)
     frame_view->bubble_border()->set_background_color(color());
+
+  // When there's an opaque layer, the bubble border background won't show
+  // through, so explicitly paint a background color.
+  set_background(layer() && layer()->fills_bounds_opaquely()
+                     ? Background::CreateSolidBackground(color())
+                     : nullptr);
 }
 
 void BubbleDialogDelegateView::HandleVisibilityChanged(Widget* widget,
                                                        bool visible) {
   if (widget == GetWidget() && anchor_widget() &&
       anchor_widget()->GetTopLevelWidget()) {
     anchor_widget()->GetTopLevelWidget()->SetAlwaysRenderAsActive(visible);
   }
 
   // Fire AX_EVENT_ALERT for bubbles marked as AX_ROLE_ALERT_DIALOG; this
   // instructs accessibility tools to read the bubble in its entirety rather
   // than just its title and initially focused view.  See
   // http://crbug.com/474622 for details.
   if (widget == GetWidget() && visible) {
     ui::AXViewState state;
     GetAccessibleState(&state);
     if (state.role == ui::AX_ROLE_ALERT_DIALOG)
       NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);
   }
 }
 
 }  // namespace views