Revert 118546 because it caused PrerenderHTML5VideoNetwork to timeout on windows and linux

media/base/download_rate_monitor.cc

Index: media/base/download_rate_monitor.cc
===================================================================
--- media/base/download_rate_monitor.cc	(revision 118589)
+++ media/base/download_rate_monitor.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -91,6 +91,8 @@
   if (stopped_)
     return;
 
+  is_downloading_data_ = true;
+
   // Check monotonically nondecreasing constraint.
   base::Time previous_time;
   if (!current_sample_.is_null())
@@ -118,11 +120,12 @@
 }
 
 void DownloadRateMonitor::SetNetworkActivity(bool is_downloading_data) {
-  // Record when download defers for the first time.
-  if (!is_downloading_data && !has_deferred_) {
-    has_deferred_ = true;
-    NotifyCanPlayThroughIfNeeded();
-  }
+  if (is_downloading_data == is_downloading_data_)
+    return;
+  // Invalidate the current sample if downloading is going from start to stopped
+  // or vice versa.
+  current_sample_.Reset();
+  is_downloading_data_ = is_downloading_data;
 }
 
 void DownloadRateMonitor::Stop() {
@@ -136,13 +139,13 @@
   has_notified_can_play_through_ = false;
   current_sample_.Reset();
   sample_window_.clear();
+  is_downloading_data_ = false;
   total_bytes_ = -1;
   buffered_bytes_ = 0;
   local_source_ = false;
   bitrate_ = 0;
   stopped_ = true;
   streaming_ = false;
-  has_deferred_ = false;
 }
 
 DownloadRateMonitor::~DownloadRateMonitor() { }
@@ -207,9 +210,8 @@
   if (local_source_ || streaming_)
     return true;
 
-  // If all bytes are buffered or if enough bytes were buffered such that
-  // downloading has deferred, fire CanPlayThrough.
-  if (buffered_bytes_ == total_bytes_ || has_deferred_)
+  // If all bytes are buffered, fire CanPlayThrough.
+  if (buffered_bytes_ == total_bytes_)
     return true;
 
   // If bitrate is unknown, optimistically fire CanPlayThrough immediately.
@@ -226,9 +228,12 @@
   if (download_rate > 0)
     return download_rate >= bytes_needed_per_second;
 
-  // With very fast connections, we may want to fire CanPlayThrough before
-  // waiting for the sample window size to reach |kNumberOfSamples|. Check for
-  // this scenario.
+  // If download rate is unknown, it may be because the media is being
+  // downloaded so fast that it cannot collect an adequate number of samples
+  // before the download gets deferred.
+  //
+  // To catch this case, we also look at how much data is being downloaded
+  // immediately after the download begins.
   if (sample_window_.size() < kNumberOfSamples) {
     int64 bytes_downloaded_since_start =
         bytes_downloaded_in_window() + current_sample_.bytes_downloaded();