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

content/common/browser_plugin_messages.h

Index: content/common/browser_plugin_messages.h
diff --git a/content/common/browser_plugin_messages.h b/content/common/browser_plugin_messages.h
index 9b9352eb22bc1d647831541749fb8d96d3d03307..5b77b4fcf225e2ca6ac77cca96c5cddcab4e4d45 100644
--- a/content/common/browser_plugin_messages.h
+++ b/content/common/browser_plugin_messages.h
@@ -234,6 +234,15 @@ IPC_MESSAGE_ROUTED3(BrowserPluginHostMsg_PluginAtPositionResponse,
 IPC_MESSAGE_ROUTED2(BrowserPluginHostMsg_SetName,
                     int /* instance_id */,
                     std::string /* name */)
+// Tells the guest that its request for media permission has been allowed or
+// denied.
+// Note that |allow| = true does not readily mean that the guest will be granted
+// permission, since a security check in the embedder will follow. The guest
+// will be granted permission only if its embedder also has access to media.
+IPC_MESSAGE_ROUTED3(BrowserPluginHostMsg_AllowMediaAccess,
+                    int /* instance_id */,
+                    int /* request_id */,
+                    bool /* allow */)
 
 // -----------------------------------------------------------------------------
 // These messages are from the guest renderer to the browser process
@@ -362,3 +371,10 @@ IPC_MESSAGE_ROUTED5(BrowserPluginMsg_BuffersSwapped,
                     std::string /* mailbox_name */,
                     int /* route_id */,
                     int /* gpu_host_id */)
+
+// When the guest requests media access, the browser process forwards this
+// request to the embeddder through this message.
+IPC_MESSAGE_ROUTED3(BrowserPluginMsg_RequestMediaAccess,
+                    int /* instance_id */,
+                    int /* request_id */,
+                    GURL /* security_origin */)