Use SkPaintFilterCanvas for paint filtering

SkDrawFilter is deprecated - convert its only Chromium client
to SkPaintFilterCanvas.

BUG=skia:3587
R=reed@google.com,robertphillips@google.com,enne@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1176393003

Cr-Commit-Position: refs/heads/master@{#334166}

6 files changed, 82 insertions, 64 deletions

diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index 45916bf..bdde0c8 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -294,8 +294,8 @@ component("skia") {
     "ext/google_logging.cc",
     "ext/image_operations.cc",
     "ext/image_operations.h",
-    "ext/opacity_draw_filter.cc",
-    "ext/opacity_draw_filter.h",
+    "ext/opacity_filter_canvas.cc",
+    "ext/opacity_filter_canvas.h",
     "ext/pixel_ref_utils.cc",
     "ext/pixel_ref_utils.h",
     "ext/platform_canvas.cc",
diff --git a/skia/ext/opacity_draw_filter.cc b/skia/ext/opacity_draw_filter.cc
deleted file mode 100644
index 10ed9e8..0000000
--- a/skia/ext/opacity_draw_filter.cc
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2013 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 "skia/ext/opacity_draw_filter.h"
-#include "third_party/skia/include/core/SkPaint.h"
-
-namespace skia {
-
-OpacityDrawFilter::OpacityDrawFilter(float opacity,
-                                     bool disable_image_filtering)
-    : alpha_(SkScalarRoundToInt(opacity * 255)),
-      disable_image_filtering_(disable_image_filtering) {}
-
-OpacityDrawFilter::~OpacityDrawFilter() {}
-
-bool OpacityDrawFilter::filter(SkPaint* paint, Type type) {
-  if (alpha_ < 255)
-    paint->setAlpha(alpha_);
-  if (disable_image_filtering_)
-    paint->setFilterQuality(kNone_SkFilterQuality);
-  return true;
-}
-
-}  // namespace skia
-
-
diff --git a/skia/ext/opacity_draw_filter.h b/skia/ext/opacity_draw_filter.h
deleted file mode 100644
index 7d11d68..0000000
--- a/skia/ext/opacity_draw_filter.h
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright 2013 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.
-
-#ifndef SKIA_EXT_OPACITY_DRAW_FILTER_H
-#define SKIA_EXT_OPACITY_DRAW_FILTER_H
-
-#include "base/values.h"
-#include "third_party/skia/include/core/SkDrawFilter.h"
-
-class SkPaint;
-
-namespace skia {
-
-// This filter allows setting an opacity on every draw call to a canvas, and to
-// disable image filtering. Note that the opacity setting is only correct in
-// very limited conditions: when there is only zero or one opaque, nonlayer
-// draw for every pixel in the surface.
-class SK_API OpacityDrawFilter : public SkDrawFilter {
- public:
-  OpacityDrawFilter(float opacity, bool disable_image_filtering);
-  ~OpacityDrawFilter() override;
-  bool filter(SkPaint* paint, SkDrawFilter::Type type) override;
-
- private:
-  int alpha_;
-  bool disable_image_filtering_;
-};
-
-}  // namespace skia
-
-#endif  // SKIA_EXT_OPACITY_DRAW_FILTER_H
-
diff --git a/skia/ext/opacity_filter_canvas.cc b/skia/ext/opacity_filter_canvas.cc
new file mode 100644
index 0000000..11c8135
--- /dev/null
+++ b/skia/ext/opacity_filter_canvas.cc
@@ -0,0 +1,40 @@
+// Copyright 2015 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 "skia/ext/opacity_filter_canvas.h"
+#include "third_party/skia/include/core/SkPaint.h"
+#include "third_party/skia/include/core/SkTLazy.h"
+
+namespace skia {
+
+OpacityFilterCanvas::OpacityFilterCanvas(SkCanvas* canvas,
+                                         float opacity,
+                                         bool disable_image_filtering)
+    : INHERITED(canvas->imageInfo().width(), canvas->imageInfo().height()),
+      alpha_(SkScalarRoundToInt(opacity * 255)),
+      disable_image_filtering_(disable_image_filtering) {
+  this->addCanvas(canvas);
+}
+
+void OpacityFilterCanvas::onFilterPaint(SkPaint* paint, Type) const {
+  if (alpha_ < 255)
+    paint->setAlpha(alpha_);
+
+  if (disable_image_filtering_)
+    paint->setFilterQuality(kNone_SkFilterQuality);
+}
+
+void OpacityFilterCanvas::onDrawPicture(const SkPicture* picture,
+                                        const SkMatrix* matrix,
+                                        const SkPaint* paint) {
+  SkTLazy<SkPaint> filteredPaint;
+  if (paint) {
+    this->onFilterPaint(filteredPaint.set(*paint), kPicture_Type);
+  }
+
+  // Unfurl pictures in order to filter nested paints.
+  this->SkCanvas::onDrawPicture(picture, matrix, filteredPaint.getMaybeNull());
+}
+
+}  // namespace skia
diff --git a/skia/ext/opacity_filter_canvas.h b/skia/ext/opacity_filter_canvas.h
new file mode 100644
index 0000000..ee3eca6e
--- /dev/null
+++ b/skia/ext/opacity_filter_canvas.h
@@ -0,0 +1,38 @@
+// Copyright 2015 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.
+
+#ifndef SKIA_EXT_OPACITY_FILTER_CANVAS_H
+#define SKIA_EXT_OPACITY_FILTER_CANVAS_H
+
+#include "third_party/skia/include/utils/SkPaintFilterCanvas.h"
+
+namespace skia {
+
+// This filter canvas allows setting an opacity on every draw call to a canvas,
+// and to disable image filtering. Note that the opacity setting is only
+// correct in very limited conditions: when there is only zero or one opaque,
+// nonlayer draw for every pixel in the surface.
+class SK_API OpacityFilterCanvas : public SkPaintFilterCanvas {
+ public:
+  OpacityFilterCanvas(SkCanvas* canvas,
+                      float opacity,
+                      bool disable_image_filtering);
+
+ protected:
+  void onFilterPaint(SkPaint* paint, Type type) const override;
+
+  void onDrawPicture(const SkPicture* picture,
+                     const SkMatrix* matrix,
+                     const SkPaint* paint) override;
+
+ private:
+  typedef SkPaintFilterCanvas INHERITED;
+
+  int alpha_;
+  bool disable_image_filtering_;
+};
+
+}  // namespace skia
+
+#endif  // SKIA_EXT_OPACITY_FILTER_CANVAS_H
diff --git a/skia/skia_chrome.gypi b/skia/skia_chrome.gypi
index eb3f7e2..0d10a43 100644
--- a/skia/skia_chrome.gypi
+++ b/skia/skia_chrome.gypi
@@ -51,8 +51,8 @@
     'ext/google_logging.cc',
     'ext/image_operations.cc',
     'ext/image_operations.h',
-    'ext/opacity_draw_filter.cc',
-    'ext/opacity_draw_filter.h',
+    'ext/opacity_filter_canvas.cc',
+    'ext/opacity_filter_canvas.h',
     'ext/pixel_ref_utils.cc',
     'ext/pixel_ref_utils.h',
     'ext/platform_canvas.cc',