Add VMMetric and some sample metrics

runtime/vm/json_stream.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_JSON_STREAM_H_
 #define VM_JSON_STREAM_H_
 
 #include "include/dart_api.h"  // for Dart_Port
 #include "platform/json.h"
 #include "vm/allocation.h"
 
 namespace dart {
 
 class DebuggerEvent;
 class Field;
 class Array;
 class GrowableObjectArray;
 class Instance;
 class JSONArray;
 class JSONObject;
 class Object;
 class SourceBreakpoint;
+class Metric;
 class Zone;
 
 class JSONStream : ValueObject {
  public:
   explicit JSONStream(intptr_t buf_size = 256);
   ~JSONStream();
 
   void Setup(Zone* zone,
              Dart_Port reply_port,
              const GrowableObjectArray& path,
@@ skipping 48 matching lines @@
   void PrintValueBool(bool b);
   void PrintValue(intptr_t i);
   void PrintValue64(int64_t i);
   void PrintValue(double d);
   void PrintValue(const char* s);
   void PrintValueNoEscape(const char* s);
   void PrintfValue(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
   void PrintValue(const Object& o, bool ref = true);
   void PrintValue(SourceBreakpoint* bpt);
   void PrintValue(const DebuggerEvent* event);
+  void PrintValue(Metric* metric);
   void PrintValue(Isolate* isolate, bool ref = true);
 
   void PrintPropertyBool(const char* name, bool b);
   void PrintProperty(const char* name, intptr_t i);
   void PrintProperty64(const char* name, int64_t i);
   void PrintProperty(const char* name, double d);
   void PrintProperty(const char* name, const char* s);
   void PrintPropertyNoEscape(const char* name, const char* s);
   void PrintfProperty(const char* name, const char* format, ...)
   PRINTF_ATTRIBUTE(3, 4);
   void PrintProperty(const char* name, const Object& o, bool ref = true);
 
   void PrintProperty(const char* name, const DebuggerEvent* event);
   void PrintProperty(const char* name, SourceBreakpoint* bpt);
+  void PrintProperty(const char* name, Metric* metric);
   void PrintProperty(const char* name, Isolate* isolate);
   void PrintPropertyName(const char* name);
   void PrintCommaIfNeeded();
   bool NeedComma();
 
   void AddEscapedUTF8String(const char* s);
 
   intptr_t nesting_level() const { return open_objects_; }
 
   intptr_t open_objects_;
@@ skipping 46 matching lines @@
   }
   void AddProperty(const char* name, const Object& obj, bool ref = true) const {
     stream_->PrintProperty(name, obj, ref);
   }
   void AddProperty(const char* name, const DebuggerEvent* event) const {
     stream_->PrintProperty(name, event);
   }
   void AddProperty(const char* name, SourceBreakpoint* bpt) const {
     stream_->PrintProperty(name, bpt);
   }
+  void AddProperty(const char* name, Metric* metric) const {
+    stream_->PrintProperty(name, metric);
+  }
   void AddProperty(const char* name, Isolate* isolate) const {
     stream_->PrintProperty(name, isolate);
   }
   void AddPropertyF(const char* name, const char* format, ...) const
       PRINTF_ATTRIBUTE(3, 4);
 
  private:
   JSONStream* stream_;
 
   friend class JSONArray;
@@ skipping 28 matching lines @@
   }
   void AddValue(Isolate* isolate, bool ref = true) const {
     stream_->PrintValue(isolate, ref);
   }
   void AddValue(SourceBreakpoint* bpt) const {
     stream_->PrintValue(bpt);
   }
   void AddValue(const DebuggerEvent* event) const {
     stream_->PrintValue(event);
   }
+  void AddValue(Metric* metric) const {
+    stream_->PrintValue(metric);
+  }
   void AddValueF(const char* format, ...) const PRINTF_ATTRIBUTE(2, 3);
 
  private:
   JSONStream* stream_;
 
   friend class JSONObject;
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(JSONArray);
 };
 
 }  // namespace dart
 
 #endif  // VM_JSON_STREAM_H_