scheduler: Tell v8 about the current RAIL mode

components/scheduler/renderer/renderer_scheduler.h

Index: components/scheduler/renderer/renderer_scheduler.h
diff --git a/components/scheduler/renderer/renderer_scheduler.h b/components/scheduler/renderer/renderer_scheduler.h
index c6116ea79bdaa61abb4c5e48d3d6257ec6c66103..ea461e06dcd50367cdc40e09970e0871770f846d 100644
--- a/components/scheduler/renderer/renderer_scheduler.h
+++ b/components/scheduler/renderer/renderer_scheduler.h
@@ -31,6 +31,10 @@ class WebLocalFrame;
 class WebThread;
 }
 
+namespace v8 {
+class Isolate;
+}
+
 namespace scheduler {
 
 class RenderWidgetSchedulingState;
@@ -43,37 +47,6 @@ class SCHEDULER_EXPORT RendererScheduler : public ChildScheduler {
   // Returns the compositor task runner.
   virtual scoped_refptr<TaskQueue> CompositorTaskRunner() = 0;
 
-  // Keep RendererScheduler::UseCaseToString in sync with this enum.
-  enum class UseCase {
-    // No active use case detected.
-    NONE,
-    // A continuous gesture (e.g., scroll, pinch) which is being driven by the
-    // compositor thread.
-    COMPOSITOR_GESTURE,
-    // An unspecified touch gesture which is being handled by the main thread.
-    // Note that since we don't have a full view of the use case, we should be
-    // careful to prioritize all work equally.
-    MAIN_THREAD_CUSTOM_INPUT_HANDLING,
-    // A continuous gesture (e.g., scroll, pinch) which is being driven by the
-    // compositor thread but also observed by the main thread. An example is
-    // synchronized scrolling where a scroll listener on the main thread changes
-    // page layout based on the current scroll position.
-    SYNCHRONIZED_GESTURE,
-    // A gesture has recently started and we are about to run main thread touch
-    // listeners to find out the actual gesture type. To minimize touch latency,
-    // only input handling work should run in this state.
-    TOUCHSTART,
-    // The page is loading.
-    LOADING,
-    // A continuous gesture (e.g., scroll) which is being handled by the main
-    // thread.
-    MAIN_THREAD_GESTURE,
-    // Must be the last entry.
-    USE_CASE_COUNT,
-    FIRST_USE_CASE = NONE,
-  };
-  static const char* UseCaseToString(UseCase use_case);
-
   // Creates a WebThread implementation for the renderer main thread.
   virtual std::unique_ptr<blink::WebThread> CreateMainThread() = 0;
 
@@ -191,6 +164,9 @@ class SCHEDULER_EXPORT RendererScheduler : public ChildScheduler {
   virtual void SetTopLevelBlameContext(
       base::trace_event::BlameContext* blame_context) = 0;
 
+  // Set the main thread's V8 isolate. Used for controlling v8's RAIL mode.
+  virtual void SetMainThreadIsolate(v8::Isolate* isolate) = 0;
+
  protected:
   RendererScheduler();
   DISALLOW_COPY_AND_ASSIGN(RendererScheduler);