Remove android_java_ui as it is not used

chrome/browser/page_load_metrics/observers/previews_page_load_metrics_observer.cc

 // Copyright 2016 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 "chrome/browser/page_load_metrics/observers/previews_page_load_metrics_observer.h"
 
 #include <string>
 
 #include "base/optional.h"
 #include "base/time/time.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
 #include "chrome/common/features.h"
 #include "chrome/common/page_load_metrics/page_load_timing.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/web_contents.h"
 
-#if BUILDFLAG(ANDROID_JAVA_UI)
+#if defined(OS_ANDROID)
 #include "chrome/browser/android/offline_pages/offline_page_tab_helper.h"
-#endif  // BUILDFLAG(ANDROID_JAVA_UI)
+#endif  // defined(OS_ANDROID)
 
 namespace previews {
 
 namespace internal {
 
 const char kHistogramOfflinePreviewsDOMContentLoadedEventFired[] =
     "PageLoad.Clients.Previews.OfflinePages.DocumentTiming."
     "NavigationToDOMContentLoadedEventFired";
 const char kHistogramOfflinePreviewsFirstLayout[] =
     "PageLoad.Clients.Previews.OfflinePages.DocumentTiming."
@@ skipping 72 matching lines @@
   if (!WasStartedInForegroundOptionalEventInForeground(
           timing.dom_content_loaded_event_start, info)) {
     return;
   }
   PAGE_LOAD_HISTOGRAM(internal::kHistogramOfflinePreviewsParseStart,
                       timing.parse_start.value());
 }
 
 bool PreviewsPageLoadMetricsObserver::IsOfflinePreview(
     content::WebContents* web_contents) const {
-#if BUILDFLAG(ANDROID_JAVA_UI)
+#if defined(OS_ANDROID)
   offline_pages::OfflinePageTabHelper* tab_helper =
       offline_pages::OfflinePageTabHelper::FromWebContents(web_contents);
   return tab_helper && tab_helper->IsShowingOfflinePreview();
 #else
   return false;
-#endif  // BUILDFLAG(ANDROID_JAVA_UI)
+#endif  // defined(OS_ANDROID)
 }
 
 }  // namespace previews