Enable detection-only mode for OomIntervention

This CL allows detection-only mode for oom intervention in order to gather
data from finch, while not actually triggering intervention (or the infobar).

Change-Id: I511bf3ccd51218521a526ea001de2a823e1c16bc
Reviewed-on: https://chromium-review.googlesource.com/c/1325583Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Yuzu Saijo <yuzus@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606389}

chrome/browser/android/oom_intervention/oom_intervention_tab_helper.cc

@@ -295,13 +295,10 @@ void OomInterventionTabHelper::StartDetectionInRenderer() {
     DCHECK(!web_contents()->GetBrowserContext()->IsOffTheRecord());
     const std::string& host = web_contents()->GetVisibleURL().host();
     if (!decider_->CanTriggerIntervention(host)) {
-      renderer_pause_enabled = false;
-      navigate_ads_enabled = false;
+      return;
     }
   }
 
-  if (!renderer_pause_enabled && !navigate_ads_enabled)
-    return;
   content::RenderFrameHost* main_frame = web_contents()->GetMainFrame();
   DCHECK(main_frame);
   content::RenderProcessHost* render_process_host = main_frame->GetProcess();

third_party/blink/renderer/controller/oom_intervention_impl.cc

@@ -53,7 +53,6 @@ OomInterventionMetrics OomInterventionImpl::GetCurrentMemoryMetrics() {
 
 void OomInterventionImpl::Check(TimerBase*) {
   DCHECK(host_);
-  DCHECK(renderer_pause_enabled_ || navigate_ads_enabled_);
 
   OomInterventionMetrics current_memory = GetCurrentMemoryMetrics();
   bool oom_detected = false;