cc: Move SkShader construction to a single spot in PaintShader

cc/paint/paint_op_buffer_unittest.cc

Index: cc/paint/paint_op_buffer_unittest.cc
diff --git a/cc/paint/paint_op_buffer_unittest.cc b/cc/paint/paint_op_buffer_unittest.cc
index 2afcdeda27c5fd73b831f45ddb9acb0775ea96c4..4cb45481dec1fdd97c76971fb0a594c9d5e392e6 100644
--- a/cc/paint/paint_op_buffer_unittest.cc
+++ b/cc/paint/paint_op_buffer_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "cc/paint/paint_op_buffer.h"
+#include "base/memory/ptr_util.h"
 #include "cc/paint/display_item_list.h"
 #include "cc/test/skia_common.h"
 #include "cc/test/test_skcanvas.h"
@@ -440,8 +441,8 @@ TEST(PaintOpBufferTest, DiscardableImagesTracking_OpWithFlags) {
   PaintOpBuffer buffer;
   PaintFlags flags;
   sk_sp<SkImage> image = CreateDiscardableImage(gfx::Size(100, 100));
-  flags.setShader(
-      image->makeShader(SkShader::kClamp_TileMode, SkShader::kClamp_TileMode));
+  flags.setShader(base::MakeUnique<PaintShader>(
+      image, SkShader::kClamp_TileMode, SkShader::kClamp_TileMode, nullptr));
   buffer.push<DrawRectOp>(SkRect::MakeWH(100, 100), flags);
   EXPECT_TRUE(buffer.HasDiscardableImages());
 }