Use combined native/manual JNI registration.

android_webview/lib/main/webview_entry_point.cc

Index: android_webview/lib/main/webview_entry_point.cc
diff --git a/android_webview/lib/main/webview_entry_point.cc b/android_webview/lib/main/webview_entry_point.cc
index 7de575a6e1c8ab6ca99e18726c6dcfc0937537e8..6827eadc1b2053aa88fadb114d24eec0fcc24938 100644
--- a/android_webview/lib/main/webview_entry_point.cc
+++ b/android_webview/lib/main/webview_entry_point.cc
@@ -9,6 +9,10 @@
 // This is called by the VM when the shared library is first loaded.
 // Most of the initialization is done in LibraryLoadedOnMainThread(), not here.
 JNI_EXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
+  // WebView uses native JNI exports; disable manual JNI registration to
+  // improve startup peformance.
+  base::android::DisableManualJniRegistration();
+
   if (!android_webview::OnJNIOnLoad(vm))
     return -1;