plumb network upload into the task manager

chrome/browser/task_manager/sampling/task_group.cc

Index: chrome/browser/task_manager/sampling/task_group.cc
diff --git a/chrome/browser/task_manager/sampling/task_group.cc b/chrome/browser/task_manager/sampling/task_group.cc
index ce8460050d72812df030d2c1fdee2f683bb1718a..22505222e072615488f9973cfb0c48fb93ace246 100644
--- a/chrome/browser/task_manager/sampling/task_group.cc
+++ b/chrome/browser/task_manager/sampling/task_group.cc
@@ -91,7 +91,8 @@ TaskGroup::TaskGroup(
       cpu_usage_(0.0),
       gpu_memory_(-1),
       memory_state_(base::MemoryState::UNKNOWN),
-      per_process_network_usage_(-1),
+      per_process_network_usage_rate_(-1),
+      cumulative_per_process_network_usage_(0),
 #if defined(OS_WIN)
       gdi_current_handles_(-1),
       gdi_peak_handles_(-1),
@@ -155,7 +156,6 @@ void TaskGroup::Refresh(const gpu::VideoMemoryUsageStats& gpu_memory_stats,
                         int64_t refresh_flags) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   DCHECK(!empty());
-
   expected_on_bg_done_flags_ = refresh_flags & kBackgroundRefreshTypesMask;
   // If a refresh type was recently disabled, we need to account for that too.
   current_on_bg_done_flags_ &= expected_on_bg_done_flags_;
@@ -165,12 +165,15 @@ void TaskGroup::Refresh(const gpu::VideoMemoryUsageStats& gpu_memory_stats,
   const bool network_usage_refresh_enabled =
       TaskManagerObserver::IsResourceRefreshEnabled(REFRESH_TYPE_NETWORK_USAGE,
                                                     refresh_flags);
-  per_process_network_usage_ = network_usage_refresh_enabled ? 0 : -1;
+
+  per_process_network_usage_rate_ = network_usage_refresh_enabled ? 0 : -1;
+  cumulative_per_process_network_usage_ = 0;

[ncarter (slow), 2017/06/20 19:52:27]

Hmm. If a Task goes away (say a tab closes) but the TaskGroup remains, it
actually looks like we would encounter a case here where
cumulative_per_process_network_usage_ would decrease, since we'd basically
forget its contribution.

This may be a benign bug, since we only collect this value for testing
currently.

Maybe the thing to do here is not reset this to zero each loop, and inside the
loop, add in the per-task delta?

Since it's benign, it would be okay to fix this in a follow-on patch set if you
like.

[cburn, 2017/06/20 21:34:55]

Ill fix it in a follow-on patch set. 

   for (Task* task : tasks_) {
     task->Refresh(update_interval, refresh_flags);
-
-    if (network_usage_refresh_enabled && task->ReportsNetworkUsage())
-      per_process_network_usage_ += task->network_usage();
+    if (network_usage_refresh_enabled) {
+      per_process_network_usage_rate_ += task->network_usage_rate();
+      cumulative_per_process_network_usage_ += task->cumulative_network_usage();
+    }
   }
 
   // 2- Refresh GPU memory (if enabled).