Plumb smooth scrolling in Chromium compositor

android_webview/native/aw_contents.cc

Index: android_webview/native/aw_contents.cc
diff --git a/android_webview/native/aw_contents.cc b/android_webview/native/aw_contents.cc
index 10c21da3a47d0c8cee5db8a275cf13124b789173..806fe967ea18e1f2cf2fbebec21f6976afc6e0fa 100644
--- a/android_webview/native/aw_contents.cc
+++ b/android_webview/native/aw_contents.cc
@@ -1066,6 +1066,19 @@ void AwContents::ScrollTo(JNIEnv* env, jobject obj, jint x, jint y) {
   browser_view_renderer_.ScrollTo(gfx::Vector2d(x, y));
 }
 
+void AwContents::SmoothScroll(JNIEnv* env,
+                              jobject obj,
+                              jint target_x,
+                              jint target_y,
+                              jlong duration_ms) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  float scale = browser_view_renderer_.dip_scale() *
+                browser_view_renderer_.page_scale_factor();
+  render_view_host_ext_->SmoothScroll(target_x / scale, target_y / scale,
+                                      duration_ms);
+}
+
 void AwContents::OnWebLayoutPageScaleFactorChanged(float page_scale_factor) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   JNIEnv* env = AttachCurrentThread();