[Telemetry] Fix smoothScrollBy on Nexus 10.

I missed a device scale place in my previous patch.

BUG=242976
TEST=tools/perf/run_measurement --browser=android-content-shell smoothness_measurement tools/perf/page_sets/top_25.json --page-filter=hl=e

Review URL: https://chromiumcodereview.appspot.com/16057003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202986 0039d316-1c4b-4281-b951-d872f2087c98

content/public/android/java/src/org/chromium/content/browser/SmoothScroller.java

@@ -72,7 +72,8 @@ public class SmoothScroller {
                 break;
             }
             case STATE_MOVING: {
-                double delta = nativeGetScrollDelta(mNativePtr, mContentViewCore.getScale());
+                double delta = nativeGetScrollDelta(
+                    mNativePtr, mContentViewCore.getRenderCoordinates().getDeviceScaleFactor());
                 if (delta != 0) {
                     mCurrentY += mScrollDown ? -delta : delta;