Shortcut a couple of IPCs when the task manager is disabled.

chrome/browser/task_manager/task_manager.cc

Index: chrome/browser/task_manager/task_manager.cc
diff --git a/chrome/browser/task_manager/task_manager.cc b/chrome/browser/task_manager/task_manager.cc
index ce2c93e1e0262b00bef8a9aa725063959da6b429..67c5f7ead06ad4e02aa6ce28a14aa1f7b477c5e9 100644
--- a/chrome/browser/task_manager/task_manager.cc
+++ b/chrome/browser/task_manager/task_manager.cc
@@ -241,6 +241,7 @@ TaskManagerModel::TaskManagerModel(TaskManager* task_manager)
       update_requests_(0),
       listen_requests_(0),
       update_state_(IDLE),
+      is_updating_byte_count_(false),
       goat_salt_(base::RandUint64()) {
   AddResourceProvider(
       new task_manager::BrowserProcessResourceProvider(task_manager));
@@ -1055,6 +1056,10 @@ void TaskManagerModel::StartUpdating() {
     FOR_EACH_OBSERVER(TaskManagerModelObserver, observer_list_,
                       OnReadyPeriodicalUpdate());
   }
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&TaskManagerModel::SetUpdatingByteCount, this, true));
 }
 
 void TaskManagerModel::StopUpdating() {
@@ -1070,6 +1075,10 @@ void TaskManagerModel::StopUpdating() {
 
   // Notify resource providers that we are done updating.
   StopListening();
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&TaskManagerModel::SetUpdatingByteCount, this, false));
 }
 
 void TaskManagerModel::StartListening() {
@@ -1244,6 +1253,8 @@ void TaskManagerModel::NotifyV8HeapStats(base::ProcessId renderer_id,
 void TaskManagerModel::NotifyBytesRead(const net::URLRequest& request,
                                        int byte_count) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (!is_updating_byte_count_)
+    return;
 
   // Only net::URLRequestJob instances created by the ResourceDispatcherHost
   // have an associated ResourceRequestInfo and a render frame associated.
@@ -1393,6 +1404,11 @@ void TaskManagerModel::NotifyMultipleBytesRead() {
                  base::Owned(bytes_read_buffer)));
 }
 
+void TaskManagerModel::SetUpdatingByteCount(bool is_updating) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  is_updating_byte_count_ = is_updating;
+}
+
 int64 TaskManagerModel::GetNetworkUsage(Resource* resource) const {
   int64 net_usage = GetNetworkUsageForResource(resource);
   if (net_usage == 0 && !resource->SupportNetworkUsage())