Blink Compositor: Erase virtuals on Transform and Filter operations.

cc/animation/transform_operations.h

Index: cc/animation/transform_operations.h
diff --git a/cc/animation/transform_operations.h b/cc/animation/transform_operations.h
index d173ace71799b54bc0613a78d8e1482d99384573..b97ba36c400f7714a5f11e586215445de44967e0 100644
--- a/cc/animation/transform_operations.h
+++ b/cc/animation/transform_operations.h
@@ -7,6 +7,7 @@
 
 #include <vector>
 
+#include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/animation/transform_operation.h"
@@ -90,6 +91,13 @@ class CC_EXPORT TransformOperations {
   void AppendIdentity();
   bool IsIdentity() const;
 
+  size_t size() const { return operations_.size(); }
+
+  const TransformOperation& at(size_t index) const {
+    DCHECK_LT(index, size());
+    return operations_[index];
+  }
+
  private:
   bool BlendInternal(const TransformOperations& from,
                      SkMScalar progress,