Move download messages from Renderer to Frame filter.

content/common/frame_messages.h

 // Copyright 2013 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.
 
 // IPC messages for interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 861 matching lines @@
 // Sent when the user wants to search for a word on the page (find-in-page).
 IPC_MESSAGE_ROUTED3(FrameMsg_Find,
                     int /* request_id */,
                     base::string16 /* search_text */,
                     blink::WebFindOptions)
 
 // This message notifies the renderer that the user has closed the find-in-page
 // window (and what action to take regarding the selection).
 IPC_MESSAGE_ROUTED1(FrameMsg_StopFinding, content::StopFindAction /* action */)
 
+// Copies the image at location x, y to the clipboard (if there indeed is an
+// image at that location).
+IPC_MESSAGE_ROUTED2(FrameMsg_CopyImageAt,
+                    int /* x */,
+                    int /* y */)
+
+// Saves the image at location x, y to the disk (if there indeed is an
+// image at that location).
+IPC_MESSAGE_ROUTED2(FrameMsg_SaveImageAt,
+                    int /* x */,
+                    int /* y */)
+
 #if defined(ENABLE_PLUGINS)
 // Notifies the renderer of updates to the Plugin Power Saver origin whitelist.
 IPC_MESSAGE_ROUTED1(FrameMsg_UpdatePluginContentOriginWhitelist,
                     std::set<url::Origin> /* origin_whitelist */)
 #endif  // defined(ENABLE_PLUGINS)
 
 // Used to instruct the RenderFrame to go into "view source" mode. This should
 // only be sent to the main frame.
 IPC_MESSAGE_ROUTED0(FrameMsg_EnableViewSourceMode)
 
@@ skipping 92 matching lines @@
 IPC_MESSAGE_ROUTED1(FrameHostMsg_DidChangeLoadProgress,
                     double /* load_progress */)
 
 // Requests that the given URL be opened in the specified manner.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_OpenURL, FrameHostMsg_OpenURL_Params)
 
 // Notifies the browser that a frame finished loading.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_DidFinishLoad,
                     GURL /* validated_url */)
 
+// Initiates a download based on user actions like 'ALT+click'.
+IPC_MESSAGE_CONTROL5(FrameHostMsg_DownloadUrl,

[asanka, 2016/05/18 16:26:54]

Shall we switch these two messages to ROUTED and skip the IDs?

[brettw, 2016/05/25 19:10:20]

This message isn't actually routed to the view. It's grabbed by the filter on
the I/O thread that then needs the parameters. If we changed it to be routed we
would need to use a lower-level message dispatch so the message handlers can get
the view IDs out. This would be more complicated.

+                     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
 // triggered the navigation timestamp.
 IPC_MESSAGE_ROUTED2(FrameHostMsg_DocumentOnLoadCompleted,
                     FrameMsg_UILoadMetricsReportType::Value /* report_type */,
                     base::TimeTicks /* ui_timestamp */)
 
 // Notifies that the initial empty document of a view has been accessed.
 // After this, it is no longer safe to show a pending navigation's URL without
@@ skipping 441 matching lines @@
 IPC_MESSAGE_ROUTED3(FrameHostMsg_FindMatchRects_Reply,
                     int /* version */,
                     std::vector<gfx::RectF> /* rects */,
                     gfx::RectF /* active_rect */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent FrameMsg, then ifdefs for platform specific FrameMsg, then
 // platform independent FrameHostMsg, then ifdefs for platform specific
 // FrameHostMsg.