Remove Timer usages from OomInterventionImpl

This is part of efforts to replace default timer task runners with
other appropriate task runners in the renderer.

Note that this CL adds a usage of default timer task queue via WebThread
::GetTaskRunner(), but I think this is inevitable.

Bug: 624694, 804694
Change-Id: I3a18dc9908850096050de16c66f3c78aa0e3c666
Reviewed-on: https://chromium-review.googlesource.com/923833Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Hajime Hoshi <hajimehoshi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537293}

third_party/WebKit/Source/controller/OomInterventionImpl.cpp

@@ -47,7 +47,9 @@ void OomInterventionImpl::Create(mojom::blink::OomInterventionRequest request) {
 OomInterventionImpl::OomInterventionImpl(
     MemoryWorkloadCaculator workload_calculator)
     : workload_calculator_(std::move(workload_calculator)),
-      timer_(this, &OomInterventionImpl::Check) {
+      timer_(Platform::Current()->MainThread()->GetTaskRunner(),
+             this,
+             &OomInterventionImpl::Check) {
   DCHECK(workload_calculator_);
 }
 

third_party/WebKit/Source/controller/OomInterventionImpl.h

@@ -41,7 +41,7 @@ class CONTROLLER_EXPORT OomInterventionImpl
   MemoryWorkloadCaculator workload_calculator_;
   mojom::blink::OomInterventionHostPtr host_;
   bool trigger_intervention_ = false;
-  Timer<OomInterventionImpl> timer_;
+  TaskRunnerTimer<OomInterventionImpl> timer_;
   std::unique_ptr<ScopedPagePauser> pauser_;
 };