<webview>: First stab at implementing media permission request for guests.

content/browser/browser_plugin/browser_plugin_guest.h

Index: content/browser/browser_plugin/browser_plugin_guest.h
diff --git a/content/browser/browser_plugin/browser_plugin_guest.h b/content/browser/browser_plugin/browser_plugin_guest.h
index f0b3039019282c15f0822198145f4d4ffb08597c..0ab7225f10e6866c3342a76bec7c0be8719301e4 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.h
+++ b/content/browser/browser_plugin/browser_plugin_guest.h
@@ -58,6 +58,7 @@ namespace content {
 class BrowserPluginHostFactory;
 class BrowserPluginEmbedder;
 class RenderProcessHost;
+struct MediaStreamRequest;
 
 // A browser plugin guest provides functionality for WebContents to operate in
 // the guest role and implements guest specific overrides for ViewHostMsg_*
@@ -147,6 +148,10 @@ class CONTENT_EXPORT BrowserPluginGuest : public NotificationObserver,
   virtual void RunFileChooser(WebContents* web_contents,
                               const FileChooserParams& params) OVERRIDE;
   virtual bool ShouldFocusPageAfterCrash() OVERRIDE;
+  virtual void RequestMediaAccessPermission(
+      WebContents* web_contents,
+      const content::MediaStreamRequest& request,
+      const content::MediaResponseCallback& callback) OVERRIDE;
 
   // Exposes the protected web_contents() from WebContentsObserver.
   WebContents* GetWebContents();
@@ -154,6 +159,7 @@ class CONTENT_EXPORT BrowserPluginGuest : public NotificationObserver,
   // Kill the guest process.
   void Terminate();
 
+
   // Overridden in tests.
   virtual void SetDamageBuffer(
       const BrowserPluginHostMsg_ResizeGuest_Params& params);
@@ -171,6 +177,11 @@ class CONTENT_EXPORT BrowserPluginGuest : public NotificationObserver,
   int instance_id() const { return instance_id_; }
 
  private:
+  typedef std::pair<content::MediaStreamRequest, content::MediaResponseCallback>
+      MediaStreamRequestAndCallbackPair;
+  typedef std::map<int, MediaStreamRequestAndCallbackPair>
+      MediaStreamRequestsMap;
+
   friend class TestBrowserPluginGuest;
 
   BrowserPluginGuest(int instance_id,
@@ -195,6 +206,12 @@ class CONTENT_EXPORT BrowserPluginGuest : public NotificationObserver,
 
   // Message handlers for messsages from embedder.
 
+  // Allows or denies a media access request, after the embedder has had a
+  // chance to decide.
+  void OnAllowPermissionAccess(int instance_id,
+                               const std::string& permission_type,
+                               int request_id,
+                               bool should_allow);
   // Handles drag events from the embedder.
   // When dragging, the drag events go to the embedder first, and if the drag
   // happens on the browser plugin, then the plugin sends a corresponding
@@ -303,6 +320,15 @@ class CONTENT_EXPORT BrowserPluginGuest : public NotificationObserver,
   gfx::Size max_auto_size_;
   gfx::Size min_auto_size_;
 
+  // A counter to generate unique request id for a media access request.
+  // We only need the ids to be unique for a given BrowserPluginGuest.
+  int current_media_access_request_id_;

[Charlie Reis, 2013/02/11 22:20:56]

Are we going to need a counter and map for each type of permission, or could one
counter and map be generalized to work for all types of permissions?  (I'm
wondering how much code bloat we're expecting here.)

[lazyboy, 2013/02/12 05:03:45]

The counter can be one, but different types of permission I've seen so far
requires to store different callbacks/states, and some doesn't require any
(pointer lock). I'm not totally sure at this point, but we can improve it once
we have more than one such requests implemented (much like how
BrowserPluginBindings got generalized).

+  // A map to store WebContents's media request object and callback.
+  // We need to store these because we need a roundtrip to the embedder to know
+  // if we allow or disallow the request. The key of the map is unique only for
+  // a given BrowserPluginGuest.
+  MediaStreamRequestsMap media_requests_map_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserPluginGuest);
 };