Align layers for ARC notification surface to pixels

ui/arc/notification/arc_custom_notification_view.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/arc/notification/arc_custom_notification_view.h"
 
+#include "ash/wm/window_util.h"
 #include "base/auto_reset.h"
 #include "base/memory/ptr_util.h"
 #include "components/exo/notification_surface.h"
 #include "components/exo/surface.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/display/screen.h"
 #include "ui/events/event_handler.h"
@@ skipping 342 matching lines @@
   SchedulePaint();
 }
 
 void ArcCustomNotificationView::AttachSurface() {
   if (!GetWidget())
     return;
 
   UpdatePreferredSize();
   Attach(surface_->window());
 
+  // The texture for this window can be placed at subpixel position
+  // with fractional scale factor. Force to align it at the pixel
+  // boundary here, and when layout is updated in Layout().
+  ash::wm::SnapWindowToPixelBoundary(surface_->window());
+
   // Creates slide helper after this view is added to its parent.
   slide_helper_.reset(new SlideHelper(this));
 
   // Invokes Update() in case surface is attached during a slide.
   slide_helper_->Update();
 }
 
 void ArcCustomNotificationView::ViewHierarchyChanged(
     const views::View::ViewHierarchyChangedDetails& details) {
   views::Widget* widget = GetWidget();
@@ skipping 46 matching lines @@
   if (!floating_close_button_widget_)
     return;
 
   gfx::Rect close_button_bounds(floating_close_button_->GetPreferredSize());
   close_button_bounds.set_x(contents_bounds.right() -
                             close_button_bounds.width());
   close_button_bounds.set_y(contents_bounds.y());
   floating_close_button_widget_->SetBounds(close_button_bounds);
 
   UpdateCloseButtonVisiblity();
+
+  ash::wm::SnapWindowToPixelBoundary(surface_->window());
 }
 
 void ArcCustomNotificationView::OnPaint(gfx::Canvas* canvas) {
   views::NativeViewHost::OnPaint(canvas);
 
   // Bail if there is a |surface_| or no item or no snapshot image.
   if (surface_ || !item_ || item_->snapshot().isNull())
     return;
   const gfx::Rect contents_bounds = GetContentsBounds();
   canvas->DrawImageInt(item_->snapshot(), 0, 0, item_->snapshot().width(),
@@ skipping 89 matching lines @@
 
 void ArcCustomNotificationView::OnNotificationSurfaceRemoved(
     exo::NotificationSurface* surface) {
   if (surface->notification_id() != notification_key_)
     return;
 
   SetSurface(nullptr);
 }
 
 }  // namespace arc