Cleanups: addressed your comments from https://codereview.chromium.org/14962008/

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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.
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
@@ skipping 1308 matching lines @@
   if (class_id == kSmiCid || class_id == kMintCid) {
     *fits = true;
     return Api::Success(isolate);
   }
   // Slow path for Mints and Bigints.
   DARTSCOPE(isolate);
   const Integer& int_obj = Api::UnwrapIntegerHandle(isolate, integer);
   if (int_obj.IsNull()) {
     RETURN_TYPE_ERROR(isolate, integer, Integer);
   }
-  ASSERT(!BigintOperations::FitsIntoMint(Bigint::Cast(int_obj)));
+  ASSERT(!BigintOperations::FitsIntoInt64(Bigint::Cast(int_obj)));
   *fits = false;
   return Api::Success(isolate);
 }
 
 
 DART_EXPORT Dart_Handle Dart_IntegerFitsIntoUint64(Dart_Handle integer,
                                                    bool* fits) {
   // Fast path for Smis.
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
@@ skipping 55 matching lines @@
   const Integer& int_obj = Api::UnwrapIntegerHandle(isolate, integer);
   if (int_obj.IsNull()) {
     RETURN_TYPE_ERROR(isolate, integer, Integer);
   }
   ASSERT(!int_obj.IsSmi());
   if (int_obj.IsMint()) {
     *value = int_obj.AsInt64Value();
     return Api::Success(isolate);
   } else {
     const Bigint& bigint = Bigint::Cast(int_obj);
-    if (BigintOperations::FitsIntoMint(bigint)) {
-      *value = BigintOperations::ToMint(bigint);
+    if (BigintOperations::FitsIntoInt64(bigint)) {
+      *value = BigintOperations::ToInt64(bigint);
       return Api::Success(isolate);
     }
   }
   return Api::NewError("%s: Integer %s cannot be represented as an int64_t.",
                        CURRENT_FUNC, int_obj.ToCString());
 }
 
 
 DART_EXPORT Dart_Handle Dart_IntegerToUint64(Dart_Handle integer,
                                              uint64_t* value) {
@@ skipping 525 matching lines @@
   } else if (retval.IsMint() || retval.IsBigint()) {
     if (retval.IsMint()) {
       int64_t mint_value = Mint::Cast(retval).value();
       if (mint_value >= kIntptrMin && mint_value <= kIntptrMax) {
         *len = static_cast<intptr_t>(mint_value);
       }
     } else {
       // Check for a non-canonical Mint range value.
       ASSERT(retval.IsBigint());
       const Bigint& bigint = Bigint::Handle();
-      if (BigintOperations::FitsIntoMint(bigint)) {
+      if (BigintOperations::FitsIntoInt64(bigint)) {
         int64_t bigint_value = bigint.AsInt64Value();
         if (bigint_value >= kIntptrMin && bigint_value <= kIntptrMax) {
           *len = static_cast<intptr_t>(bigint_value);
         }
       }
     }
     return Api::NewError("Length of List object is greater than the "
                          "maximum value that 'len' parameter can hold");
   } else if (retval.IsError()) {
     return Api::NewHandle(isolate, retval.raw());
@@ skipping 2907 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success(isolate);
 }
 
 }  // namespace dart