Update stopwatch to use patching to share sources instead of exposing

runtime/lib/stopwatch.cc

Index: runtime/lib/stopwatch.cc
diff --git a/runtime/lib/clock.cc b/runtime/lib/stopwatch.cc
similarity index 81%
rename from runtime/lib/clock.cc
rename to runtime/lib/stopwatch.cc
index 1a07623c4c9fb4d2de49d5ee3dcb16a3ddebffb2..10eebdc73d0456a7d5fec8f22a16269b34f81c97 100644
--- a/runtime/lib/clock.cc
+++ b/runtime/lib/stopwatch.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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.
 
@@ -9,7 +9,7 @@
 
 namespace dart {
 
-DEFINE_NATIVE_ENTRY(Clock_now, 0) {
+DEFINE_NATIVE_ENTRY(Stopwatch_now, 0) {
   // TODO(iposva): investigate other hi-res time sources such as cycle count.
   const Integer& micros =
       Integer::Handle(Integer::New(OS::GetCurrentTimeMicros()));
@@ -17,7 +17,7 @@ DEFINE_NATIVE_ENTRY(Clock_now, 0) {
 }
 
 
-DEFINE_NATIVE_ENTRY(Clock_frequency, 0) {
+DEFINE_NATIVE_ENTRY(Stopwatch_frequency, 0) {
   // TODO(iposva): investigate other hi-res time sources such as cycle count.
   const Integer& frequency = Integer::Handle(Integer::New(1000000));
   arguments->SetReturn(frequency);