[Cross-Site Isolation] Migrate entire MediaStream verticals to be per-RenderFrame.

chrome/browser/media/desktop_streams_registry.cc

 // 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.
 
 #include "chrome/browser/media/desktop_streams_registry.h"
 
 #include "base/base64.h"
 #include "base/location.h"
 #include "base/time/time.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 13 matching lines @@
                      &result);
   return result;
 }
 
 }  // namespace
 
 DesktopStreamsRegistry::DesktopStreamsRegistry() {}
 DesktopStreamsRegistry::~DesktopStreamsRegistry() {}
 
 std::string DesktopStreamsRegistry::RegisterStream(
-    int render_process_id,
-    int render_view_id,
+    const content::WebContents* web_contents,
     const GURL& origin,
     const content::DesktopMediaID& source,
     const std::string& extension_name) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   std::string id = GenerateRandomStreamId();
   ApprovedDesktopMediaStream& stream = approved_streams_[id];
-  stream.render_process_id = render_process_id;
-  stream.render_view_id = render_view_id;
+  DCHECK(web_contents);
+  stream.web_contents = web_contents;
   stream.origin = origin;
   stream.source = source;
   stream.extension_name = extension_name;
 
   content::BrowserThread::PostDelayedTask(
       content::BrowserThread::UI, FROM_HERE,
       base::Bind(&DesktopStreamsRegistry::CleanupStream,
                  base::Unretained(this), id),
       base::TimeDelta::FromSeconds(kApprovedStreamTimeToLiveSeconds));
 
   return id;
 }
 
 content::DesktopMediaID DesktopStreamsRegistry::RequestMediaForStreamId(
     const std::string& id,
-    int render_process_id,
-    int render_view_id,
+    const content::WebContents* web_contents,
     const GURL& origin,
     std::string* extension_name) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   StreamsMap::iterator it = approved_streams_.find(id);
 
   // Verify that if there is a request with the specified ID it was created for
   // the same origin and the same renderer.
   if (it == approved_streams_.end() ||
-      render_process_id != it->second.render_process_id ||
-      render_view_id != it->second.render_view_id ||
+      web_contents != it->second.web_contents ||

[ncarter (slow), 2014/07/10 01:17:51]

You can only match against a pointer value like this if you can guarantee that
the value in the map is not stored past the lifetime of the WebContents --
otherwise the memory, once freed, could be reallocated as a different
WebContents. Routing pairs were not unsafe in that way, since they are never
reused.

I think this file should probably go back to using a process_id / routing_id
pair, with the routing_id becoming a RFH routing ID instead of an RVH one.

[miu, 2014/07/10 22:16:12]

Done.

       origin != it->second.origin) {
     return content::DesktopMediaID();
   }
 
   content::DesktopMediaID result = it->second.source;
   *extension_name = it->second.extension_name;
   approved_streams_.erase(it);
   return result;
 }
 
 void DesktopStreamsRegistry::CleanupStream(const std::string& id) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   approved_streams_.erase(id);
 }
 
 DesktopStreamsRegistry::ApprovedDesktopMediaStream::ApprovedDesktopMediaStream()
-    : render_process_id(-1), render_view_id(-1) {}
+    : web_contents(NULL) {}