Don't notify the task manager about bytes read from the cache.

chrome/browser/net/chrome_network_delegate.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 "chrome/browser/net/chrome_network_delegate.h"
 
 #include <stdlib.h>
 
 #include <vector>
 
@@ skipping 520 matching lines @@
 }
 
 void ChromeNetworkDelegate::OnRawBytesRead(const net::URLRequest& request,
                                            int bytes_read) {
   TRACE_EVENT_ASYNC_STEP_PAST1("net", "URLRequest", &request, "DidRead",
                                "bytes_read", bytes_read);
   performance_monitor::PerformanceMonitor::GetInstance()->BytesReadOnIOThread(
       request, bytes_read);
 
 #if defined(ENABLE_TASK_MANAGER)
-  TaskManager::GetInstance()->model()->NotifyBytesRead(request, bytes_read);
+  // This is not completely accurate, but as a first approximation ignore
+  // requests that are served from the cache. See bug 330931 for more info.
+  if (!request.was_cached())
+    TaskManager::GetInstance()->model()->NotifyBytesRead(request, bytes_read);
 #endif  // defined(ENABLE_TASK_MANAGER)
 }
 
 void ChromeNetworkDelegate::OnCompleted(net::URLRequest* request,
                                         bool started) {
   TRACE_EVENT_ASYNC_END0("net", "URLRequest", request);
   if (request->status().status() == net::URLRequestStatus::SUCCESS) {
     // For better accuracy, we use the actual bytes read instead of the length
     // specified with the Content-Length header, which may be inaccurate,
     // or missing, as is the case with chunked encoding.
@@ skipping 248 matching lines @@
     spdyproxy::DataReductionRequestType data_reduction_type) {
   DCHECK_GE(received_content_length, 0);
   DCHECK_GE(original_content_length, 0);
   StoreAccumulatedContentLength(received_content_length,
                                 original_content_length,
                                 data_reduction_type,
                                 reinterpret_cast<Profile*>(profile_));
   received_content_length_ += received_content_length;
   original_content_length_ += original_content_length;
 }