Use Thread::Current()/MainThread() in bindings/ and controller/.

This CL simplifies lengthy function calls via Platform::Current() that
obtain the current thread and the main thread by using Thread::Current()
and Thread::MainThread().

Also now-redundant null checks for those functions are removed.

Bug: 826203
Change-Id: Iedfd7f09b5334dc84fa921cdca84ca39ad9b3af9
Reviewed-on: https://chromium-review.googlesource.com/c/1318773Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Yuta Kitamura <yutak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605600}

third_party/blink/renderer/bindings/core/v8/dom_wrapper_world_test.cc

@@ -116,7 +116,7 @@ TEST(DOMWrapperWorldTest, Basic) {
       ThreadCreationParams(WebThreadType::kTestThread)
           .SetThreadNameForTest("DOMWrapperWorld test thread"));
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner =
-      Platform::Current()->CurrentThread()->GetTaskRunner();
+      Thread::Current()->GetTaskRunner();
   thread->BackingThread().PostTask(
       FROM_HERE,
       CrossThreadBind(&WorkerThreadFunc, CrossThreadUnretained(thread.get()),

third_party/blink/renderer/controller/blink_initializer.cc

@@ -123,19 +123,14 @@ void InitializeCommon(Platform* platform,
 
   GetBlinkInitializer().RegisterInterfaces(*registry);
 
-  // currentThread is null if we are running on a thread without a message loop.
-  if (Thread* current_thread = platform->CurrentThread()) {
-    DCHECK(!g_end_of_task_runner);
-    g_end_of_task_runner = new EndOfTaskRunner;
-    current_thread->AddTaskObserver(g_end_of_task_runner);
-  }
+  DCHECK(!g_end_of_task_runner);
+  g_end_of_task_runner = new EndOfTaskRunner;
+  Thread::Current()->AddTaskObserver(g_end_of_task_runner);
 
-  if (Thread* main_thread = Platform::Current()->MainThread()) {
-    scoped_refptr<base::SequencedTaskRunner> task_runner =
-        main_thread->GetTaskRunner();
-    if (task_runner)
-      MemoryAblationExperiment::MaybeStartForRenderer(task_runner);
-  }
+  scoped_refptr<base::SequencedTaskRunner> task_runner =
+      Thread::MainThread()->GetTaskRunner();
+  if (task_runner)
+    MemoryAblationExperiment::MaybeStartForRenderer(task_runner);
 
 #if defined(OS_ANDROID)
   // Initialize CrashMemoryMetricsReporterImpl in order to assure that memory
@@ -164,10 +159,10 @@ void CreateMainThreadAndInitialize(Platform* platform,
 void BlinkInitializer::RegisterInterfaces(
     service_manager::BinderRegistry& registry) {
   ModulesInitializer::RegisterInterfaces(registry);
-  Thread* main_thread = Platform::Current()->MainThread();
+  Thread* main_thread = Thread::MainThread();
   // GetSingleThreadTaskRunner() uses GetTaskRunner() internally.
   // crbug.com/781664
-  if (!main_thread || !main_thread->GetTaskRunner())
+  if (!main_thread->GetTaskRunner())
     return;
 
 #if defined(OS_ANDROID)

third_party/blink/renderer/controller/blink_leak_detector.cc

@@ -25,7 +25,7 @@
 namespace blink {
 
 BlinkLeakDetector::BlinkLeakDetector()
-    : delayed_gc_timer_(Platform::Current()->CurrentThread()->GetTaskRunner(),
+    : delayed_gc_timer_(Thread::Current()->GetTaskRunner(),
                         this,
                         &BlinkLeakDetector::TimerFiredGC) {}
 

third_party/blink/renderer/controller/oom_intervention_impl.cc

@@ -23,7 +23,7 @@ void OomInterventionImpl::Create(mojom::blink::OomInterventionRequest request) {
 }
 
 OomInterventionImpl::OomInterventionImpl()
-    : timer_(Platform::Current()->MainThread()->GetTaskRunner(),
+    : timer_(Thread::MainThread()->GetTaskRunner(),
              this,
              &OomInterventionImpl::Check) {}