cc: Move SkShader construction to a single spot in PaintShader

cc/paint/paint_shader.h

 // Copyright 2017 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 CC_PAINT_PAINT_SHADER_H_
 #define CC_PAINT_PAINT_SHADER_H_
 
-#include "cc/paint/paint_record.h"
+#include <memory>
+
+#include "cc/paint/paint_export.h"
 #include "third_party/skia/include/core/SkImage.h"
+#include "third_party/skia/include/core/SkScalar.h"
 #include "third_party/skia/include/core/SkShader.h"
 
 namespace cc {
-using PaintShader = SkShader;
 
-inline sk_sp<PaintShader> WrapSkShader(sk_sp<SkShader> shader) {
-  return shader;
-}
+class PaintOpBuffer;
+using PaintRecord = PaintOpBuffer;
 
-inline sk_sp<PaintShader> MakePaintShaderImage(sk_sp<const SkImage> image,
-                                               SkShader::TileMode tx,
-                                               SkShader::TileMode ty,
-                                               const SkMatrix* local_matrix) {
-  return image->makeShader(tx, ty, local_matrix);
-}
+class CC_PAINT_EXPORT PaintShader {
+ public:
+  static std::unique_ptr<PaintShader> MakeColor(SkColor color);
 
-inline sk_sp<PaintShader> MakePaintShaderRecord(sk_sp<PaintRecord> record,
-                                                const SkRect& tile,
+  static std::unique_ptr<PaintShader> MakeLinearGradient(
+      const SkPoint points[],
+      const SkColor colors[],
+      const SkScalar pos[],
+      int count,
+      SkShader::TileMode mode,
+      uint32_t flags = 0,
+      const SkMatrix* local_matrix = nullptr,
+      SkColor fallback_color = SK_ColorTRANSPARENT);
+
+  static std::unique_ptr<PaintShader> MakeRadialGradient(
+      const SkPoint& center,
+      SkScalar radius,
+      const SkColor colors[],
+      const SkScalar pos[],
+      int color_count,
+      SkShader::TileMode mode,
+      uint32_t flags = 0,
+      const SkMatrix* local_matrix = nullptr,
+      SkColor fallback_color = SK_ColorTRANSPARENT);
+
+  static std::unique_ptr<PaintShader> MakeTwoPointConicalGradient(
+      const SkPoint& start,
+      SkScalar start_radius,
+      const SkPoint& end,
+      SkScalar end_radius,
+      const SkColor colors[],
+      const SkScalar pos[],
+      int color_count,
+      SkShader::TileMode mode,
+      uint32_t flags = 0,
+      const SkMatrix* local_matrix = nullptr,
+      SkColor fallback_color = SK_ColorTRANSPARENT);
+
+  static std::unique_ptr<PaintShader> MakeSweepGradient(
+      SkScalar cx,
+      SkScalar cy,
+      const SkColor colors[],
+      const SkScalar pos[],
+      int color_count,
+      uint32_t flags = 0,
+      const SkMatrix* local_matrix = nullptr,
+      SkColor fallback_color = SK_ColorTRANSPARENT);
+
+  static std::unique_ptr<PaintShader> MakeImage(sk_sp<const SkImage> image,
                                                 SkShader::TileMode tx,
                                                 SkShader::TileMode ty,
-                                                const SkMatrix* local_matrix) {
-  return SkShader::MakePictureShader(ToSkPicture(record, tile), tx, ty,
-                                     local_matrix, nullptr);
-}
+                                                const SkMatrix* local_matrix);
+
+  static std::unique_ptr<PaintShader> MakePaintRecord(
+      sk_sp<PaintRecord> record,
+      const SkRect& tile,
+      SkShader::TileMode tx,
+      SkShader::TileMode ty,
+      const SkMatrix* local_matrix);
+
+  PaintShader(const PaintShader& other);
+  PaintShader(PaintShader&& other);
+  ~PaintShader();
+
+  PaintShader& operator=(const PaintShader& other);
+  PaintShader& operator=(PaintShader&& other);
+
+  const sk_sp<SkShader>& sk_shader() const { return sk_shader_; }
+
+ private:
+  PaintShader(sk_sp<SkShader> shader, SkColor fallback_color);
+
+  sk_sp<SkShader> sk_shader_;
+};
 
 }  // namespace cc
 
 #endif  // CC_PAINT_PAINT_SHADER_H_