Remove page IDs from three WebContentsObserver APIs that don't need it.

content/browser/android/web_contents_observer_android.cc

Index: content/browser/android/web_contents_observer_android.cc
diff --git a/content/browser/android/web_contents_observer_android.cc b/content/browser/android/web_contents_observer_android.cc
index 9a0d56ac26f9514f5a64396fb25b92333ee05b15..db50efc8eb3fc645c5ef789290f7bf06b40f4338 100644
--- a/content/browser/android/web_contents_observer_android.cc
+++ b/content/browser/android/web_contents_observer_android.cc
@@ -273,13 +273,13 @@ void WebContentsObserverAndroid::DidFailLoadInternal(
       jstring_error_description.obj(), jstring_url.obj());
 }
 
-void WebContentsObserverAndroid::DidFirstVisuallyNonEmptyPaint(int32 page_id) {
+void WebContentsObserverAndroid::DidFirstVisuallyNonEmptyPaint() {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj(weak_java_observer_.get(env));
   if (obj.is_null())
     return;
   Java_WebContentsObserverAndroid_didFirstVisuallyNonEmptyPaint(
-      env, obj.obj(), page_id);
+      env, obj.obj());
 }
 
 bool RegisterWebContentsObserverAndroid(JNIEnv* env) {