Cleanup: Use std::atomic<T> instead of base::AtomicNumber<T> in TaskRunner.

Bug: chromium:842083
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I6b3f60526718f782b075bd450282646d97f6f9b5
Reviewed-on: https://chromium-review.googlesource.com/1131124Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54385}

test/inspector/task-runner.cc

@@ -41,7 +41,8 @@ TaskRunner::TaskRunner(IsolateData::SetupGlobalTasks setup_global_tasks,
       ready_semaphore_(ready_semaphore),
       data_(nullptr),
       process_queue_semaphore_(0),
-      nested_loop_count_(0) {
+      nested_loop_count_(0),
+      is_terminated_(0) {
   Start();
 }
 
@@ -56,7 +57,7 @@ void TaskRunner::Run() {
 
 void TaskRunner::RunMessageLoop(bool only_protocol) {
   int loop_number = ++nested_loop_count_;
-  while (nested_loop_count_ == loop_number && !is_terminated_.Value()) {
+  while (nested_loop_count_ == loop_number && !is_terminated_) {
     TaskRunner::Task* task = GetNext(only_protocol);
     if (!task) return;
     v8::Isolate::Scope isolate_scope(isolate());
@@ -88,13 +89,13 @@ void TaskRunner::Append(Task* task) {
 }
 
 void TaskRunner::Terminate() {
-  is_terminated_.Increment(1);
+  is_terminated_++;
   process_queue_semaphore_.Signal();
 }
 
 TaskRunner::Task* TaskRunner::GetNext(bool only_protocol) {
   for (;;) {
-    if (is_terminated_.Value()) return nullptr;
+    if (is_terminated_) return nullptr;
     if (only_protocol) {
       Task* task = nullptr;
       if (queue_.Dequeue(&task)) {

test/inspector/task-runner.h

@@ -10,7 +10,6 @@
 #include "include/v8-inspector.h"
 #include "include/v8-platform.h"
 #include "include/v8.h"
-#include "src/base/atomic-utils.h"
 #include "src/base/macros.h"
 #include "src/base/platform/platform.h"
 #include "src/locked-queue-inl.h"
@@ -64,7 +63,7 @@ class TaskRunner : public v8::base::Thread {
 
   int nested_loop_count_;
 
-  v8::base::AtomicNumber<int> is_terminated_;
+  std::atomic<int> is_terminated_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskRunner);
 };