Move platform abstraction to base library

src/code-stubs-hydrogen.cc

Index: src/code-stubs-hydrogen.cc
diff --git a/src/code-stubs-hydrogen.cc b/src/code-stubs-hydrogen.cc
index 05d422604ef9a0d06cfe221bec58a706e9d1fceb..cce31d936808ea871dc8ea0798b134441dc41a9d 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -262,7 +262,7 @@ static Handle<Code> DoGenerateCode(Stub* stub) {
     ASSERT(!descriptor->stack_parameter_count().is_valid());
     return stub->GenerateLightweightMissCode();
   }
-  ElapsedTimer timer;
+  base::ElapsedTimer timer;
   if (FLAG_profile_hydrogen_code_stub_compilation) {
     timer.Start();
   }