Initial UserTag and dart:profiler library

runtime/vm/profiler.h

 // 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.
 
 #ifndef VM_PROFILER_H_
 #define VM_PROFILER_H_
 
 #include "vm/allocation.h"
 #include "vm/code_observers.h"
 #include "vm/globals.h"
@@ skipping 131 matching lines @@
   }
 
   uword vm_tag() const {
     return vm_tag_;
   }
   void set_vm_tag(uword tag) {
     ASSERT(tag != VMTag::kInvalidTagId);
     vm_tag_ = tag;
   }
 
+  uword user_tag() const {
+    return user_tag_;
+  }
+  void set_user_tag(uword tag) {
+    user_tag_ = tag;
+  }
+
  private:
   int64_t timestamp_;
   ThreadId tid_;
   Isolate* isolate_;
   uword vm_tag_;
+  uword user_tag_;
   uword pcs_[kSampleFramesSize];
 };
 
 
 // Ring buffer of Samples that is (usually) shared by many isolates.
 class SampleBuffer {
  public:
   static const intptr_t kDefaultBufferCapacity = 120000;  // 2 minutes @ 1000hz.
 
   explicit SampleBuffer(intptr_t capacity = kDefaultBufferCapacity) {
@@ skipping 50 matching lines @@
   intptr_t capacity_;
   uintptr_t cursor_;
 
   DISALLOW_COPY_AND_ASSIGN(SampleBuffer);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_PROFILER_H_