Add ink drop masking to TrayBackgroundView

ui/views/animation/ink_drop_mask.cc

Index: ui/views/animation/ink_drop_mask.cc
diff --git a/ui/views/animation/ink_drop_mask.cc b/ui/views/animation/ink_drop_mask.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3b64ac0b8da2d79cbf0849deb77771805273b81b
--- /dev/null
+++ b/ui/views/animation/ink_drop_mask.cc
@@ -0,0 +1,68 @@
+// 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/animation/ink_drop_mask.h"
+
+#include "third_party/skia/include/core/SkPaint.h"
+#include "ui/compositor/paint_recorder.h"
+#include "ui/gfx/canvas.h"
+
+namespace views {
+
+// InkDropMask
+
+InkDropMask::InkDropMask(const gfx::Rect& layer_bounds)
+    : layer_(ui::LAYER_TEXTURED) {
+  layer_.set_delegate(this);
+  layer_.SetBounds(layer_bounds);
+  layer_.SetFillsBoundsOpaquely(false);
+  layer_.set_name("InkDropMaskLayer");
+}
+
+InkDropMask::~InkDropMask() {
+  layer_.set_delegate(nullptr);
+}
+
+void InkDropMask::OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) {}
+
+void InkDropMask::OnDeviceScaleFactorChanged(float device_scale_factor) {}
+
+// RoundRectInkDropMask
+
+RoundRectInkDropMask::RoundRectInkDropMask(const gfx::Rect& layer_bounds,
+                                           const gfx::Rect& mask_bounds,
+                                           int corner_radius)
+    : InkDropMask(layer_bounds),
+      mask_bounds_(mask_bounds),
+      corner_radius_(corner_radius) {}
+
+void RoundRectInkDropMask::OnPaintLayer(const ui::PaintContext& context) {
+  SkPaint paint;
+  paint.setAlpha(255);
+  paint.setStyle(SkPaint::kFill_Style);
+  paint.setAntiAlias(true);
+
+  ui::PaintRecorder recorder(context, layer()->size());
+  recorder.canvas()->DrawRoundRect(mask_bounds_, corner_radius_, paint);
+}
+
+// CircleInkDropMask
+
+CircleInkDropMask::CircleInkDropMask(const gfx::Rect& layer_bounds,
+                                     const gfx::Point& mask_center,
+                                     int mask_radius)
+    : InkDropMask(layer_bounds),
+      mask_center_(mask_center),
+      mask_radius_(mask_radius) {}
+
+void CircleInkDropMask::OnPaintLayer(const ui::PaintContext& context) {
+  SkPaint paint;
+  paint.setAlpha(255);
+  paint.setStyle(SkPaint::kFill_Style);
+
+  ui::PaintRecorder recorder(context, layer()->size());
+  recorder.canvas()->DrawCircle(mask_center_, mask_radius_, paint);
+}
+
+}  // namespace views