Remove most native WebContents references from Java

chrome/browser/android/chrome_web_contents_delegate_android.cc

Index: chrome/browser/android/chrome_web_contents_delegate_android.cc
diff --git a/chrome/browser/android/chrome_web_contents_delegate_android.cc b/chrome/browser/android/chrome_web_contents_delegate_android.cc
index 3a9413ec03814916e7aba0b7a354995dd31da97b..038a27467b9ea005d6f39a9f75e796aebcea2c0c 100644
--- a/chrome/browser/android/chrome_web_contents_delegate_android.cc
+++ b/chrome/browser/android/chrome_web_contents_delegate_android.cc
@@ -322,11 +322,18 @@ void ChromeWebContentsDelegateAndroid::AddNewContents(
   ScopedJavaLocalRef<jobject> obj = GetJavaDelegate(env);
   bool handled = false;
   if (!obj.is_null()) {
+    ScopedJavaLocalRef<jobject> jsource;
+    if (source)
+      jsource = source->GetJavaWebContents();
+    ScopedJavaLocalRef<jobject> jnew_contents;
+    if (new_contents)
+      jnew_contents = new_contents->GetJavaWebContents();
+
     handled = Java_ChromeWebContentsDelegateAndroid_addNewContents(
         env,
         obj.obj(),
-        reinterpret_cast<intptr_t>(source),
-        reinterpret_cast<intptr_t>(new_contents),
+        jsource.obj(),
+        jnew_contents.obj(),
         static_cast<jint>(disposition),
         NULL,
         user_gesture);