TaskManager: use an unordered_map for tracking network usage

chrome/browser/task_manager/task_manager_interface.cc

Index: chrome/browser/task_manager/task_manager_interface.cc
diff --git a/chrome/browser/task_manager/task_manager_interface.cc b/chrome/browser/task_manager/task_manager_interface.cc
index 2b833ec9c0053cd49d15b7de6ec20358e384619e..3a8fddbbf75ec79cdc8d5e805dd5df46ffba0bd2 100644
--- a/chrome/browser/task_manager/task_manager_interface.cc
+++ b/chrome/browser/task_manager/task_manager_interface.cc
@@ -6,7 +6,6 @@
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/task_manager/sampling/task_manager_impl.h"
-#include "chrome/browser/task_manager/sampling/task_manager_io_thread_helper.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_registry_simple.h"
@@ -40,18 +39,11 @@ TaskManagerInterface* TaskManagerInterface::GetTaskManager() {
 }
 
 // static
-void TaskManagerInterface::OnRawBytesRead(const net::URLRequest& request,
-                                          int64_t bytes_read) {
+void TaskManagerInterface::OnRawBytesTransferred(BytesTransferredKey key,

[ncarter (slow), 2017/06/29 23:40:01]

As suggested by the comment in chrome_network_delegate, let's go back to the
previous signatures for TaskManagerInterface::OnRawBytesRead and
TaskManagerInterface::OnRawBytesSent, as before.

Do the request-to-BytesTransferredKey conversion in this file.

And, rather than copying the the BytesTransferredKey computation code into both
the Sent and Read functions, I suggest actually introducing an
anonymous-namespace helper function like this:

namespace {

BytesTransferredKey KeyForRequest(const net::URLRequest& request) {
  // computation ...

  return {origin_pid, child_id, route_id};  // C++ is amazing!
}

}  // namespace

[cburn, 2017/06/30 18:04:39]

Done.

+                                                 int64_t bytes_read,
+                                                 int64_t bytes_sent) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-
-  TaskManagerIoThreadHelper::OnRawBytesRead(request, bytes_read);
-}
-
-// static
-void TaskManagerInterface::OnRawBytesSent(const net::URLRequest& request,
-                                          int64_t bytes_sent) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-  TaskManagerIoThreadHelper::OnRawBytesSent(request, bytes_sent);
+  TaskManagerIoThreadHelper::OnRawBytesTransferred(key, bytes_read, bytes_sent);
 }
 
 void TaskManagerInterface::AddObserver(TaskManagerObserver* observer) {