Move download messages from Renderer to Frame filter.

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index d8e5931037314370feaff3f5ee0e54216d962fb8..358955841c27e002f2b89e751d5178ef6d0cf8b1 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -981,6 +981,22 @@ IPC_MESSAGE_ROUTED1(FrameHostMsg_OpenURL, FrameHostMsg_OpenURL_Params)
 IPC_MESSAGE_ROUTED1(FrameHostMsg_DidFinishLoad,
                     GURL /* validated_url */)
 
+// Initiates a download based on user actions like 'ALT+click'.
+IPC_MESSAGE_CONTROL5(FrameHostMsg_DownloadUrl,
+                     int /* render_view_id */,
+                     int /* render_frame_id */,
+                     GURL /* url */,
+                     content::Referrer /* referrer */,
+                     base::string16 /* suggested_name */)
+
+// Asks the browser to save a image (for <canvas> or <img>) from a data URL.
+// Note: |data_url| is the contents of a data:URL, and that it's represented as
+// a string only to work around size limitations for GURLs in IPC messages.
+IPC_MESSAGE_CONTROL3(FrameHostMsg_SaveImageFromDataURL,
+                     int /* render_view_id */,
+                     int /* render_frame_id */,
+                     std::string /* data_url */)
+
 // Sent when after the onload handler has been invoked for the document
 // in this frame. Sent for top-level frames. |report_type| and |ui_timestamp|
 // are used to report navigation metrics starting on the ui input event that