Use portable stack slot constants in profiler

runtime/vm/profiler.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 "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
 #include "vm/code_patcher.h"
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/native_symbol.h"
 #include "vm/object.h"
 #include "vm/os.h"
 #include "vm/profiler.h"
 #include "vm/signal_handler.h"
 #include "vm/simulator.h"
+#include "vm/stack_frame.h"
 
 namespace dart {
 
 
 #if defined(USING_SIMULATOR) || defined(TARGET_OS_WINDOWS) || \
     defined(TARGET_OS_MACOS) || defined(TARGET_OS_ANDROID)
   DEFINE_FLAG(bool, profile, false, "Enable Sampling Profiler");
 #else
   DEFINE_FLAG(bool, profile, true, "Enable Sampling Profiler");
 #endif
@@ skipping 784 matching lines @@
     }
     // Move the lower bound up.
     lower_bound_ = reinterpret_cast<uintptr_t>(fp);
   }
   return i;
 }
 
 
 uword* ProfilerSampleStackWalker::CallerPC(uword* fp) {
   ASSERT(fp != NULL);
-  return reinterpret_cast<uword*>(*(fp + 1));
+  return reinterpret_cast<uword*>(*(fp + kSavedCallerPcSlotFromFp));
 }
 
 
 uword* ProfilerSampleStackWalker::CallerFP(uword* fp) {
   ASSERT(fp != NULL);
-  return reinterpret_cast<uword*>(*fp);
+  return reinterpret_cast<uword*>(*(fp + kSavedCallerFpSlotFromFp));
 }
 
 
 bool ProfilerSampleStackWalker::ValidFramePointer(uword* fp) {
   if (fp == NULL) {
     return false;
   }
   uintptr_t cursor = reinterpret_cast<uintptr_t>(fp);
   cursor += sizeof(fp);
   bool r = cursor >= lower_bound_ && cursor < stack_upper_;
   return r;
 }
 
 
 }  // namespace dart