Switch LatencyInfo struct to use a map.

cc/debug/latency_info.cc

Index: cc/debug/latency_info.cc
diff --git a/cc/debug/latency_info.cc b/cc/debug/latency_info.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e8b386816d154014912c13e6df38282124ff5b82
--- /dev/null
+++ b/cc/debug/latency_info.cc
@@ -0,0 +1,29 @@
+// Copyright (c) 2013 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 "cc/debug/latency_info.h"
+
+#include <algorithm>
+
+namespace cc {
+
+void LatencyInfo::MergeWith(const LatencyInfo& other) {
+  for (LatencyMap::const_iterator b = other.latency_numbers.begin();
+      b != other.latency_numbers.end(); ++b) {
+    AddLatencyNumber(b->first.first, b->first.second, b->second);
+  }
+}
+
+void LatencyInfo::AddLatencyNumber(LatencyComponent component,
+                                   int64 id, int64 number) {

[nduca, 2013/04/09 23:15:08]

lgtm

numer-> component_sequence_number?


lets evolve this api as we add consumers... we really want random-new-person to
be able to grok this.

+  LatencyMap::key_type key = std::make_pair(component, id);
+  LatencyMap::iterator f = latency_numbers.find(key);
+  if (f == latency_numbers.end())
+    latency_numbers[key] = number;
+  else
+    f->second = std::max(number, f->second);
+}
+
+} // namespace cc
+