[Android] Add a flag to disable the pull-to-refresh effect

android_webview/lib/main/aw_main_delegate.cc

Index: android_webview/lib/main/aw_main_delegate.cc
diff --git a/android_webview/lib/main/aw_main_delegate.cc b/android_webview/lib/main/aw_main_delegate.cc
index 04c4a175a9110a5f4284ea18899b4a0e78451f7d..c28e3d5afcacb581a53c6691a5f4d5aca021c619 100644
--- a/android_webview/lib/main/aw_main_delegate.cc
+++ b/android_webview/lib/main/aw_main_delegate.cc
@@ -62,6 +62,9 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   // WebView uses the Android system's scrollbars and overscroll glow.
   cl->AppendSwitch(switches::kDisableOverscrollEdgeEffect);
 
+  // Pull-to-refresh should never be a default WebView action.
+  cl->AppendSwitch(switches::kDisablePullToRefreshEffect);
+
   // Not yet supported in single-process mode.
   cl->AppendSwitch(switches::kDisableSharedWorkers);