Refactor SkRecord opts, converting playback optimizations where possible.

tests/RecordTest.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 
 #include "SkRecord.h"
 #include "SkRecords.h"
 
 // Sums the area of any DrawRect command it sees.
 class AreaSummer {
 public:
     AreaSummer() : fArea(0) {}
 
     template <typename T> void operator()(const T&) { }
 
     int area() const { return fArea; }
 
+    void apply(const SkRecord& record) {
+        for (unsigned i = 0; i < record.count(); i++) {
+            record.visit(i, *this);
+        }
+    }
+
 private:
     int fArea;
 };
 template <> void AreaSummer::operator()(const SkRecords::DrawRect& record) {
     fArea += (int) (record.rect.width() * record.rect.height());
 }
 
 // Scales out the bottom-right corner of any DrawRect command it sees by 2x.
 struct Stretch {
     template <typename T> void operator()(T*) {}
+
+    void apply(SkRecord* record) {
+        for (unsigned i = 0; i < record->count(); i++) {
+            record->mutate(i, *this);
+        }
+    }
 };
 template <> void Stretch::operator()(SkRecords::DrawRect* record) {
     record->rect.fRight *= 2;
     record->rect.fBottom *= 2;
 }
 
 // Basic tests for the low-level SkRecord code.
 DEF_TEST(Record, r) {
     SkRecord record;
 
     // Add a simple DrawRect command.
     SkRect rect = SkRect::MakeWH(10, 10);
     SkPaint paint;
     SkNEW_PLACEMENT_ARGS(record.append<SkRecords::DrawRect>(), SkRecords::DrawRect, (rect, paint));
 
     // Its area should be 100.
     AreaSummer summer;
-    record.visit(summer);
+    summer.apply(record);
     REPORTER_ASSERT(r, summer.area() == 100);
 
     // Scale 2x.
     Stretch stretch;
-    record.mutate(stretch);
+    stretch.apply(&record);
 
     // Now its area should be 100 + 400.
-    record.visit(summer);
+    summer.apply(record);
     REPORTER_ASSERT(r, summer.area() == 500);
 }