Enable download page action for error page

chrome/browser/net/net_error_tab_helper.cc

Index: chrome/browser/net/net_error_tab_helper.cc
diff --git a/chrome/browser/net/net_error_tab_helper.cc b/chrome/browser/net/net_error_tab_helper.cc
index 8b257b5fa2b42ac9f24499fff870ef4f334f88c8..ac28129061214589033ccb9dbc32cfa60749bb1f 100644
--- a/chrome/browser/net/net_error_tab_helper.cc
+++ b/chrome/browser/net/net_error_tab_helper.cc
@@ -142,7 +142,10 @@ bool NetErrorTabHelper::OnMessageReceived(
 #if BUILDFLAG(ANDROID_JAVA_UI)
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(NetErrorTabHelper, message)
-    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_DownloadPageLater, DownloadPageLater)
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_DownloadPageLater,
+                        OnDownloadPageLater)
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SetIsShowingDownloadButtonInErrorPage,
+                        OnSetIsShowingDownloadButtonInErrorPage)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -158,6 +161,9 @@ NetErrorTabHelper::NetErrorTabHelper(WebContents* contents)
       is_error_page_(false),
       dns_error_active_(false),
       dns_error_page_committed_(false),
+#if BUILDFLAG(ANDROID_JAVA_UI)
+      is_showing_download_button_in_error_page_(false),
+#endif  // BUILDFLAG(ANDROID_JAVA_UI)
       dns_probe_status_(error_page::DNS_PROBE_POSSIBLE),
       weak_factory_(this) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ -210,7 +216,7 @@ void NetErrorTabHelper::OnDnsProbeFinished(DnsProbeStatus result) {
 }
 
 #if BUILDFLAG(ANDROID_JAVA_UI)
-void NetErrorTabHelper::DownloadPageLater() {
+void NetErrorTabHelper::OnDownloadPageLater() {
   // Makes sure that this is coming from an error page.
   content::NavigationEntry* entry =
       web_contents()->GetController().GetLastCommittedEntry();
@@ -224,6 +230,10 @@ void NetErrorTabHelper::DownloadPageLater() {
 
   DownloadPageLaterHelper(url);
 }
+
+void NetErrorTabHelper::OnSetIsShowingDownloadButtonInErrorPage(bool show) {

[mmenke, 2017/01/09 20:35:39]

"show" seems a bit short.  Maybe just showing_button or
is_showing_download_button.

[jianli, 2017/01/09 23:35:07]

Done.

+  is_showing_download_button_in_error_page_ = show;
+}
 #endif  // BUILDFLAG(ANDROID_JAVA_UI)
 
 void NetErrorTabHelper::InitializePref(WebContents* contents) {