Back PaintRecord with PaintOpBuffer instead of SkPicture

cc/paint/paint_flags.h

Index: cc/paint/paint_flags.h
diff --git a/cc/paint/paint_flags.h b/cc/paint/paint_flags.h
index b7e96c68e2ec48f4a5e9505a7c5ce3e3e1372aee..37b460d6bda362ebe2dcb7efa9ecac7133174319 100644
--- a/cc/paint/paint_flags.h
+++ b/cc/paint/paint_flags.h
@@ -7,7 +7,6 @@
 
 #include "base/compiler_specific.h"
 #include "cc/paint/paint_export.h"
-#include "cc/paint/paint_shader.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColorFilter.h"
 #include "third_party/skia/include/core/SkDrawLooper.h"
@@ -19,6 +18,8 @@
 
 namespace cc {
 
+using PaintShader = SkShader;
+
 class CC_PAINT_EXPORT PaintFlags {
  public:
   enum Style {
@@ -198,6 +199,14 @@ class CC_PAINT_EXPORT PaintFlags {
     return paint_.computeFastBounds(orig, storage);
   }
 
+  bool operator==(const PaintFlags& flags) { return flags.paint_ == paint_; }
+  bool operator!=(const PaintFlags& flags) { return flags.paint_ != paint_; }
+
+  // Returns true if this just represents an opacity blend when
+  // used as saveLayer flags.
+  bool IsSimpleOpacity() const;
+  bool SupportsFoldingAlpha() const;
+
  private:
   friend const SkPaint& ToSkPaint(const PaintFlags& flags);
   friend const SkPaint* ToSkPaint(const PaintFlags* flags);