Address review comments for r39595.

runtime/vm/flow_graph_range_analysis.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_FLOW_GRAPH_RANGE_ANALYSIS_H_
 #define VM_FLOW_GRAPH_RANGE_ANALYSIS_H_
 
 #include "vm/flow_graph.h"
 #include "vm/intermediate_language.h"
 
@@ skipping 407 matching lines @@
   Range Intersect(const Range* other) const {
     return Range(RangeBoundary::IntersectionMin(min(), other->min()),
                  RangeBoundary::IntersectionMax(max(), other->max()));
   }
 
   bool Fits(RangeBoundary::RangeSize size) const {
     return !min().LowerBound().Overflowed(size) &&
            !max().UpperBound().Overflowed(size);
   }
 
-  static bool Fits(Range* range, RangeBoundary::RangeSize size) {
-    return !IsUnknown(range) && range->Fits(size);
-  }
-
   // Clamp this to be within size.
   void Clamp(RangeBoundary::RangeSize size);
 
   static void Add(const Range* left_range,
                   const Range* right_range,
                   RangeBoundary* min,
                   RangeBoundary* max,
                   Definition* left_defn);
 
   static void Sub(const Range* left_range,
@@ skipping 36 matching lines @@
                        const Range* right_range,
                        Definition* left_defn,
                        Range* result);
 
  private:
   RangeBoundary min_;
   RangeBoundary max_;
 };
 
 
+class RangeUtils : public AllStatic  {
+ public:
+  static bool Fits(Range* range, RangeBoundary::RangeSize size) {
+    return !Range::IsUnknown(range) && range->Fits(size);
+  }
+
+  static bool IsWithin(Range* range, int64_t min, int64_t max) {
+    return !Range::IsUnknown(range) && range->IsWithin(min, max);
+  }
+};
+
+
 // Range analysis for integer values.
 class RangeAnalysis : public ValueObject {
  public:
   explicit RangeAnalysis(FlowGraph* flow_graph)
       : flow_graph_(flow_graph),
         smi_range_(Range::Full(RangeBoundary::kRangeBoundarySmi)) { }
 
   // Infer ranges for all values and remove overflow checks from binary smi
   // operations when proven redundant.
   void Analyze();
@@ skipping 124 matching lines @@
   BitVector* selected_uint32_defs_;
 
   FlowGraph* flow_graph_;
   Isolate* isolate_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_RANGE_ANALYSIS_H_