Add queued_time_ms trace for events in message loop

base/location.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/location.h"
+#include "base/debug/trace_event.h"
+#include "base/json/string_escape.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
 #include "build/build_config.h"
 
 #if defined(COMPILER_MSVC)
 // MSDN says to #include <intrin.h>, but that breaks the VS2005 build.
 extern "C" {
   void* _ReturnAddress();
 }
 #endif
 
-#include "base/location.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/stringprintf.h"
+namespace {
+
+class LocationConvertableToTraceFormat
+    : public base::debug::ConvertableToTraceFormat {
+ public:
+  LocationConvertableToTraceFormat(const char* function_name,
+                                   const char* file_name)
+      : function_name_(function_name),
+        file_name_(file_name) {
+  }
+
+  virtual void AppendAsTraceFormat(std::string* out) const OVERRIDE {
+    out->append("\"");
+    base::JsonDoubleQuote(function_name_, false, out);
+    out->append("@");
+    base::JsonDoubleQuote(file_name_, false, out);
+    out->append("\"");
+  }
+
+ private:
+  const char* function_name_;
+  const char* file_name_;
+};

[jar (doing other things), 2013/07/08 23:14:19]

nit: NO_DEFAULT_COPY_OR_ASSIGN

+
+}  // namespace
 
 namespace tracked_objects {
 
 Location::Location(const char* function_name,
                    const char* file_name,
                    int line_number,
                    const void* program_counter)
     : function_name_(function_name),
       file_name_(file_name),
       line_number_(line_number),
       program_counter_(program_counter) {
 }
 
 Location::Location()
     : function_name_("Unknown"),
       file_name_("Unknown"),
       line_number_(-1),
       program_counter_(NULL) {
 }
 
 std::string Location::ToString() const {
   return std::string(function_name_) + "@" + file_name_ + ":" +
       base::IntToString(line_number_);
 }
 
+scoped_ptr<base::debug::ConvertableToTraceFormat>
+    Location::ToTraceFormat() const {
+  return scoped_ptr<base::debug::ConvertableToTraceFormat>(
+      new LocationConvertableToTraceFormat(function_name_, file_name_));
+}
+
 void Location::Write(bool display_filename, bool display_function_name,
                      std::string* output) const {
   base::StringAppendF(output, "%s[%d] ",
       display_filename ? file_name_ : "line",
       line_number_);
 
   if (display_function_name) {
     WriteFunctionName(output);
     output->push_back(' ');
   }
@@ skipping 41 matching lines @@
 #if defined(COMPILER_MSVC)
   return _ReturnAddress();
 #elif defined(COMPILER_GCC)
   return __builtin_extract_return_addr(__builtin_return_address(0));
 #endif  // COMPILER_GCC
 
   return NULL;
 }
 
 }  // namespace tracked_objects