Enable download page action for error page

chrome/common/render_messages.h

Index: chrome/common/render_messages.h
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index cdd991f1e06cbfd3c66007e3955a619aec684277..45d770ec2e42226d465d73024e6b8d94b78ed8c3 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -341,6 +341,11 @@ IPC_MESSAGE_ROUTED5(ChromeViewMsg_SetNavigationCorrectionInfo,
 // Message sent from the renderer to the browser to schedule to download the
 // page at a later time.
 IPC_MESSAGE_ROUTED0(ChromeViewHostMsg_DownloadPageLater)
+
+// Message sent from the renderer to the browser to indicate if download button
+// is being shown in error page.
+IPC_MESSAGE_ROUTED1(ChromeViewHostMsg_SetIsShowingDownloadButtonInErrorPage,
+                    bool /* showing download button */)
 #endif  // defined(OS_ANDROID)
 
 //-----------------------------------------------------------------------------