Move cc/debug/latency_info to ui/base.

ui/base/latency_info.cc

+// 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 "ui/base/latency_info.h"
+
+#include <algorithm>
+
+namespace ui {
+
+LatencyInfo::LatencyInfo() {
+}
+
+LatencyInfo::~LatencyInfo() {
+}
+
+void LatencyInfo::MergeWith(const LatencyInfo& other) {
+  for (LatencyMap::const_iterator it = other.latency_components.begin();
+       it != other.latency_components.end();
+       ++it) {
+    AddLatencyNumberWithTimestamp(it->first.first,
+                                  it->first.second,
+                                  it->second.sequence_number,
+                                  it->second.event_time,
+                                  it->second.event_count);
+  }
+}
+
+void LatencyInfo::AddLatencyNumber(LatencyComponentType component,
+                                   int64 id,
+                                   int64 component_sequence_number) {
+  AddLatencyNumberWithTimestamp(component, id, component_sequence_number,
+                                base::TimeTicks::Now(), 1);
+}
+
+void LatencyInfo::AddLatencyNumberWithTimestamp(LatencyComponentType component,
+                                                int64 id,
+                                                int64 component_sequence_number,
+                                                base::TimeTicks time,
+                                                uint32 event_count) {
+  LatencyMap::key_type key = std::make_pair(component, id);
+  LatencyMap::iterator it = latency_components.find(key);
+  if (it == latency_components.end()) {
+    LatencyComponent info = {component_sequence_number, time, event_count};
+    latency_components[key] = info;
+    return;
+  }
+  it->second.sequence_number = std::max(component_sequence_number,
+                                        it->second.sequence_number);
+  uint32 new_count = event_count + it->second.event_count;
+  if (event_count > 0 && new_count != 0) {
+    // Do a weighted average, so that the new event_time is the average of
+    // the times of events currently in this structure with the time passed
+    // into this method.
+    it->second.event_time += (time - it->second.event_time) * event_count /
+        new_count;
+    it->second.event_count = new_count;
+  }
+}
+
+void LatencyInfo::Clear() {
+  latency_components.clear();
+}
+
+}  // namespace ui
+