[TaskManager] Allow a Task to mutate its PID after creation

chrome/browser/task_manager/providers/task.h

Index: chrome/browser/task_manager/providers/task.h
diff --git a/chrome/browser/task_manager/providers/task.h b/chrome/browser/task_manager/providers/task.h
index a3e91ceeeb21cf116c49c285f3bac1ca7f0957a6..dc6134afe53ebacc686d4f6eb567a3dc92e4102d 100644
--- a/chrome/browser/task_manager/providers/task.h
+++ b/chrome/browser/task_manager/providers/task.h
@@ -21,6 +21,8 @@ class Profile;
 
 namespace task_manager {
 
+class TaskProviderObserver;
+
 // Defines a task that corresponds to a tab, an app, an extension, ... etc. It
 // represents one row in the task manager table. Multiple tasks can share the
 // same process, in which case they're grouped together in the task manager
@@ -83,6 +85,11 @@ class Task {
   virtual void Refresh(const base::TimeDelta& update_interval,
                        int64_t refresh_flags);
 
+  // Temporarily remove a task, change its process ID, and then re-add it.

[afakhry, 2017/08/01 17:25:35]

Nit: Looking at this comment again, I think it would be better to change it. For
example:

- ("this" task) instead of ("a" task).
- remove and re-add where? To |observer| for instance.

I'll leave the wording for you since you're better than me at this! :)

[ncarter (slow), 2017/08/01 23:07:09]

Done.

+  void UpdateProcessInfo(base::ProcessHandle handle,
+                         base::ProcessId process_id,
+                         TaskProviderObserver* observer);
+
   // Will receive this notification through the task manager from
   // |ChromeNetworkDelegate::OnNetworkBytesReceived()|. The task will add to the
   // |current_byte_count_| in this refresh cycle.
@@ -180,10 +187,10 @@ class Task {
   gfx::ImageSkia icon_;
 
   // The handle of the process on which this task is running.
-  const base::ProcessHandle process_handle_;
+  base::ProcessHandle process_handle_;
 
   // The PID of the process on which this task is running.
-  const base::ProcessId process_id_;
+  base::ProcessId process_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Task);
 };