Added tracking of time spent waiting on extensions to the webRequest API.

chrome/browser/extensions/extension_webrequest_time_tracker.h

Index: chrome/browser/extensions/extension_webrequest_time_tracker.h
diff --git a/chrome/browser/extensions/extension_webrequest_time_tracker.h b/chrome/browser/extensions/extension_webrequest_time_tracker.h
new file mode 100755
index 0000000000000000000000000000000000000000..e1c86f97119de8cd5d681c2b1916d72489752f0d
--- /dev/null
+++ b/chrome/browser/extensions/extension_webrequest_time_tracker.h
@@ -0,0 +1,95 @@
+// Copyright (c) 2011 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBREQUEST_TIME_TRACKER_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBREQUEST_TIME_TRACKER_H_
+#pragma once
+
+#include <map>
+#include <queue>
+#include <set>
+#include <string>
+
+#include "base/time.h"
+#include "base/gtest_prod_util.h"
+#include "googleurl/src/gurl.h"
+
+namespace base {
+class Time;
+}
+
+// This class keeps monitors how much delay extensions add to network requests
+// by using the webRequest API. If the delay is sufficient, we will warn the
+// user that extensions are slowing down the browser.
+class ExtensionWebRequestTimeTracker {
+ public:
+  ExtensionWebRequestTimeTracker();
+  ~ExtensionWebRequestTimeTracker();
+
+  // Records the time that a request was created.
+  void LogRequestStartTime(int64 request_id, const base::Time& start_time,
+                           const GURL& url);
+
+  // Records the time that a request either completed or encountered an error.
+  void LogRequestEndTime(int64 request_id, const base::Time& end_time);
+
+  // Records an additional delay for the given request caused by the given
+  // extension.
+  void IncrementExtensionBlockTime(
+      const std::string& extension_id,
+      int64 request_id,
+      const base::TimeDelta& block_time);
+
+  // Records an additional delay for the given request caused by all extensions
+  // combined.
+  void IncrementTotalBlockTime(
+      int64 request_id,
+      const base::TimeDelta& block_time);
+
+  // Called when an extension has canceled the given request.
+  void SetRequestCanceled(int64 request_id);
+
+  // Called when an extension has redirected the given request to another URL.
+  void SetRequestRedirected(int64 request_id);
+
+ private:
+  // Timing information for a single request.
+  struct RequestTimeLog {
+    GURL url;  // used for debug purposes only
+    bool completed;
+    base::Time request_start_time;
+    base::TimeDelta request_duration;
+    base::TimeDelta block_duration;
+    std::map<std::string, base::TimeDelta> extension_block_durations;
+    RequestTimeLog();
+    ~RequestTimeLog();
+  };
+
+  // Called after a request finishes, to analyze the delays and warn the user
+  // if necessary.
+  void Analyze(int64 request_id);
+
+  // A map of recent request IDs to timing info for each request.
+  std::map<int64, RequestTimeLog> request_time_logs_;
+
+  // A list of recent request IDs that we know about. Used to limit the size of
+  // the logs.
+  std::queue<int64> request_ids_;
+
+  // The set of recent requests that have been delayed either a large or
+  // moderate amount by extensions.
+  std::set<int64> excessive_delays_;
+  std::set<int64> moderate_delays_;
+
+  FRIEND_TEST_ALL_PREFIXES(ExtensionWebRequestTimeTrackerTest, Basic);
+  FRIEND_TEST_ALL_PREFIXES(ExtensionWebRequestTimeTrackerTest,
+                           IgnoreFastRequests);
+  FRIEND_TEST_ALL_PREFIXES(ExtensionWebRequestTimeTrackerTest,
+                           CancelOrRedirect);
+  FRIEND_TEST_ALL_PREFIXES(ExtensionWebRequestTimeTrackerTest, Delays);
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionWebRequestTimeTracker);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBREQUEST_TIME_TRACKER_H_