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}

cc/output/software_renderer.cc

@@ -20,7 +20,7 @@
 #include "cc/quads/solid_color_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "cc/quads/tile_draw_quad.h"
-#include "skia/ext/opacity_draw_filter.h"
+#include "skia/ext/opacity_filter_canvas.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkImageFilter.h"
@@ -387,23 +387,26 @@ void SoftwareRenderer::DrawPictureQuad(const DrawingFrame* frame,
       SkMatrix::kFill_ScaleToFit);
   current_canvas_->concat(content_matrix);
 
-  // TODO(aelias): This isn't correct in all cases. We should detect these
-  // cases and fall back to a persistent bitmap backing
-  // (http://crbug.com/280374).
-  skia::RefPtr<SkDrawFilter> opacity_filter = skia::AdoptRef(
-      new skia::OpacityDrawFilter(quad->shared_quad_state->opacity,
-                                  frame->disable_picture_quad_image_filtering ||
-                                      quad->nearest_neighbor));
-  DCHECK(!current_canvas_->getDrawFilter());
-  current_canvas_->setDrawFilter(opacity_filter.get());
-
-  TRACE_EVENT0("cc",
-               "SoftwareRenderer::DrawPictureQuad");
-
-  quad->raster_source->PlaybackToSharedCanvas(
-      current_canvas_, quad->content_rect, quad->contents_scale);
-
-  current_canvas_->setDrawFilter(NULL);
+  const bool needs_transparency =
+      SkScalarRoundToInt(quad->shared_quad_state->opacity * 255) < 255;
+  const bool disable_image_filtering =
+      frame->disable_picture_quad_image_filtering || quad->nearest_neighbor;
+
+  TRACE_EVENT0("cc", "SoftwareRenderer::DrawPictureQuad");
+
+  if (needs_transparency || disable_image_filtering) {
+    // TODO(aelias): This isn't correct in all cases. We should detect these
+    // cases and fall back to a persistent bitmap backing
+    // (http://crbug.com/280374).
+    skia::OpacityFilterCanvas filtered_canvas(current_canvas_,
+                                              quad->shared_quad_state->opacity,
+                                              disable_image_filtering);
+    quad->raster_source->PlaybackToSharedCanvas(
+        &filtered_canvas, quad->content_rect, quad->contents_scale);
+  } else {
+    quad->raster_source->PlaybackToSharedCanvas(
+        current_canvas_, quad->content_rect, quad->contents_scale);
+  }
 }
 
 void SoftwareRenderer::DrawSolidColorQuad(const DrawingFrame* frame,

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",

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

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

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',