[M56 fork] Disable webview async ondraw

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 6236e19f0bcb67929e3b13b53d2c741bd4bbd522..da499c783fec6056ed21500c46fa2dae1b5d92fa 100644
--- a/android_webview/lib/main/aw_main_delegate.cc
+++ b/android_webview/lib/main/aw_main_delegate.cc
@@ -66,6 +66,9 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
 
   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
 
+  // Temporarily disable async ondraw for M56.
+  cl->AppendSwitch(switches::kSyncOnDrawHardware);
+
   // WebView uses the Android system's scrollbars and overscroll glow.
   cl->AppendSwitch(switches::kDisableOverscrollEdgeEffect);