rlz: Always specify thread affinity when posting tasks

*** Note: There is no behavior change from this patch. ***

The PostTask APIs will shortly be changed to require all tasks to explicitly
specify their thread affinity, i.e., whether the task should run on the thread
pool or a specific named thread such as a BrowserThread. This patch updates all
call sites with thread affinity annotation. We also remove the "WithTraits"
suffix to make the call sites more readable.

Before:

    // Thread pool task.
    base::PostTaskWithTraits(FROM_HERE, {...}, ...);

    // UI thread task.
    base::PostTaskWithTraits(FROM_HERE, {BrowserThread::UI, ...}, ...);

After:

    // Thread pool task.
    base::PostTask(FROM_HERE, {base::ThreadPool(), ...}, ...);

    // UI thread task.
    base::PostTask(FROM_HERE, {BrowserThread::UI, ...}, ...);

This patch was semi-automatically prepared with these steps:

    1. Patch in https://chromium-review.googlesource.com/c/chromium/src/+/1635827
       to make thread affinity a build-time requirement.
    2. Run an initial pass with a clang rewriter:
       https://chromium-review.googlesource.com/c/chromium/src/+/1635623
    3. ninja -C out/Debug | grep 'requested here' | cut -d: -f1-3 | sort | \
           uniq > errors.txt
    4. while read line; do
         f=$(echo $line | cut -d: -f 1)
         r=$(echo $line | cut -d: -f 2)
         c=$(echo $line | cut -d: -f 3)
         sed -i "${r}s/./&base::ThreadPool(),/$c" $f
       done < errors.txt
    5. GOTO 3 until build succeeds.
    6. Remove the "WithTraits" suffix from task API call sites:

       $ tools/git/mffr.py -i <(cat <<EOF
       [
         ["PostTaskWithTraits",                            "PostTask"],
         ["PostDelayedTaskWithTraits",                     "PostDelayedTask"],
         ["PostTaskWithTraitsAndReply",                    "PostTaskAndReply"],
         ["CreateTaskRunnerWithTraits",                    "CreateTaskRunner"],
         ["CreateSequencedTaskRunnerWithTraits",           "CreateSequencedTaskRunner"],
         ["CreateUpdateableSequencedTaskRunnerWithTraits", "CreateUpdateableSequencedTaskRunner"],
         ["CreateSingleThreadTaskRunnerWithTraits",        "CreateSingleThreadTaskRunner"],
         ["CreateCOMSTATaskRunnerWithTraits",              "CreateCOMSTATaskRunner"]
       ]
       EOF
       )

This CL was uploaded by git cl split.

R=rogerta@chromium.org

Bug: 968047
Change-Id: Ie0678d17a9847458418eaa08e0832295d70e5e5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1729216
Auto-Submit: Sami Kyöstilä <skyostil@chromium.org>
Reviewed-by: Roger Tawa <rogerta@chromium.org>
Commit-Queue: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682711}

rlz/lib/financial_ping.cc

@@ -260,9 +260,9 @@ void ShutdownCheck(scoped_refptr<RefCountedWaitableEvent> event) {
   // How frequently the financial ping thread should check
   // the shutdown condition?
   const base::TimeDelta kInterval = base::TimeDelta::FromMilliseconds(500);
-  base::PostDelayedTaskWithTraits(FROM_HERE, {base::TaskPriority::BEST_EFFORT},
-                                  base::BindOnce(&ShutdownCheck, event),
-                                  kInterval);
+  base::PostDelayedTask(FROM_HERE,
+                        {base::ThreadPool(), base::TaskPriority::BEST_EFFORT},
+                        base::BindOnce(&ShutdownCheck, event), kInterval);
 }
 #endif
 
@@ -390,15 +390,16 @@ FinancialPing::PingResponse FinancialPing::PingServer(const char* request,
 
   base::subtle::Release_Store(&g_cancelShutdownCheck, 0);
 
-  base::PostTaskWithTraits(FROM_HERE, {base::TaskPriority::BEST_EFFORT},
-                           base::BindOnce(&ShutdownCheck, event));
+  base::PostTask(FROM_HERE,
+                 {base::ThreadPool(), base::TaskPriority::BEST_EFFORT},
+                 base::BindOnce(&ShutdownCheck, event));
 
   // PingRlzServer must be run in a separate sequence so that the TimedWait()
   // call below does not block the URL fetch response from being handled by
   // the URL delegate.
   scoped_refptr<base::SequencedTaskRunner> background_runner(
-      base::CreateSequencedTaskRunnerWithTraits(
-          {base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN,
+      base::CreateSequencedTaskRunner(
+          {base::ThreadPool(), base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN,
            base::TaskPriority::BEST_EFFORT}));
   background_runner->PostTask(FROM_HERE,
                               base::BindOnce(&PingRlzServer, url, event));