Splits SmoothGestureController from RenderWidgetHostImpl

tools/telemetry/telemetry/page/actions/scroll.js

Index: tools/telemetry/telemetry/page/actions/scroll.js
diff --git a/tools/telemetry/telemetry/page/actions/scroll.js b/tools/telemetry/telemetry/page/actions/scroll.js
index 2ccfecee77acb68e13964f6cc248150cdbad8207..32952cc5d2c79993bcd68d8a145a744f76d7d3bc 100644
--- a/tools/telemetry/telemetry/page/actions/scroll.js
+++ b/tools/telemetry/telemetry/page/actions/scroll.js
@@ -73,9 +73,13 @@
         chrome.gpuBenchmarking &&
         chrome.gpuBenchmarking.smoothScrollBy) {
       var rect = getBoundingVisibleRect(this.element_);
-      chrome.gpuBenchmarking.smoothScrollBy(distance, function() {
-        callback();
-      }, rect.left + rect.width / 2, rect.top + rect.height / 2);
+      var scrolled = chrome.gpuBenchmarking.smoothScrollBy(
+          distance, function() {
+              callback();
+          },
+          rect.left + rect.width / 2, rect.top + rect.height / 2);
+      if (!scrolled)
+        console.log('Unable to start smooth scrolling');
       return;
     }