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

content/browser/android/web_contents_observer_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/web_contents_observer_android.h"
 
 #include <string>
 
 #include <jni.h>
 
@@ skipping 255 matching lines @@
       ConvertUTF8ToJavaString(env, url.spec()));
 
   Java_WebContentsObserverAndroid_didFailLoad(
       env, obj.obj(),
       is_provisional_load,
       is_main_frame,
       error_code,
       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) {
   return RegisterNativesImpl(env);
 }
 }  // namespace content