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 342c98c4c15dc2250a8012b6d9c5d9c39ce85b37..d5e3827ed5a6f9342bfa56c4cf23e902be1ed553 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)
 
 //-----------------------------------------------------------------------------