[scheduler] Use Finch to control background throttling.

third_party/WebKit/Source/web/WebViewImpl.h

Index: third_party/WebKit/Source/web/WebViewImpl.h
diff --git a/third_party/WebKit/Source/web/WebViewImpl.h b/third_party/WebKit/Source/web/WebViewImpl.h
index d7b4643dfd8c589f14b37a752b394bda025bfda6..1246fa977620e3c7ea7e008c7ff326d47c4185e6 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.h
+++ b/third_party/WebKit/Source/web/WebViewImpl.h
@@ -100,7 +100,8 @@ class WEB_EXPORT WebViewImpl final
       public RefCounted<WebViewImpl>,
       WTF_NON_EXPORTED_BASE(public WebGestureCurveTarget),
       public PageWidgetEventHandler,
-      public WebScheduler::InterventionReporter {
+      public WebScheduler::InterventionReporter,
+      public WebScheduler::WebSchedulerSettings {
  public:
   static WebViewImpl* create(WebViewClient*, WebPageVisibilityState);
   static HashSet<WebViewImpl*>& allInstances();
@@ -279,6 +280,12 @@ class WEB_EXPORT WebViewImpl final
   // WebScheduler::InterventionReporter implementation:
   void ReportIntervention(const WebString& message) override;
 
+  // WebScheduler::WebSchedulerSettings implementation:
+  float expensiveBackgroundThrottlingCPUBudget() override;
+  float expensiveBackgroundThrottlingInitialBudget() override;
+  float expensiveBackgroundThrottlingMaxBudget() override;
+  float expensiveBackgroundThrottlingMaxDelay() override;
+
   void didUpdateFullscreenSize();
 
   float defaultMinimumPageScaleFactor() const;
@@ -749,7 +756,7 @@ class WEB_EXPORT WebViewImpl final
 
   WebPageImportanceSignals m_pageImportanceSignals;
 
-  const std::unique_ptr<WebViewScheduler> m_scheduler;
+  std::unique_ptr<WebViewScheduler> m_scheduler;
 
   double m_lastFrameTimeMonotonic;