BrowserCdmManager: gets RenderFrameHost instance on the correct thread.

content/browser/media/cdm/browser_cdm_manager.cc

Index: content/browser/media/cdm/browser_cdm_manager.cc
diff --git a/content/browser/media/cdm/browser_cdm_manager.cc b/content/browser/media/cdm/browser_cdm_manager.cc
index d3d4630cb08b54547ac2494d541e47b9589d7875..262c03fe40eb3dbba536014438ce3cdbdca5ed85 100644
--- a/content/browser/media/cdm/browser_cdm_manager.cc
+++ b/content/browser/media/cdm/browser_cdm_manager.cc
@@ -248,25 +248,26 @@ void BrowserCdmManager::OnCreateSession(
   }
   GURL security_origin = iter->second;
 
-  RenderFrameHost* rfh =
-      RenderFrameHost::FromID(render_process_id_, render_frame_id);
-  WebContents* web_contents = WebContents::FromRenderFrameHost(rfh);
-  DCHECK(web_contents);
-  GetContentClient()->browser()->RequestPermission(
-      content::PERMISSION_PROTECTED_MEDIA,
-      web_contents,
-      0,  // bridge id
-      security_origin,
-      // Only implemented for Android infobars which do not support
-      // user gestures.
-      true,
-      base::Bind(&BrowserCdmManager::CreateSessionIfPermitted,
-                 this,
-                 render_frame_id,
-                 cdm_id,
-                 session_id,
-                 mime_type,
-                 init_data));
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&BrowserCdmManager::RequestSessionPermission,
+                   this,
+                   render_frame_id,
+                   security_origin,
+                   cdm_id,
+                   session_id,
+                   mime_type,
+                   init_data));
+    return;
+  }
+  RequestSessionPermission(render_frame_id,
+                           security_origin,
+                           cdm_id,
+                           session_id,
+                           mime_type,
+                           init_data);

[xhwang, 2014/11/17 23:38:17]

Can you do the thread check and post within RequestSessionPermission()? This
function is already too long...

[gunsch, 2014/11/19 21:59:01]

Done.

 }
 
 void BrowserCdmManager::OnUpdateSession(
@@ -356,6 +357,35 @@ void BrowserCdmManager::RemoveCdm(uint64 id) {
   }
 }
 
+void BrowserCdmManager::RequestSessionPermission(
+    int render_frame_id,
+    const GURL& security_origin,
+    int cdm_id,
+    uint32 session_id,
+    const std::string& content_type,
+    const std::vector<uint8>& init_data) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);

[xhwang, 2014/11/17 23:38:17]

See comment above. Check thread and post RequestSessionPermission() if we are
not on the right thread.

[gunsch, 2014/11/19 21:59:01]

Done.

+  RenderFrameHost* rfh =
+      RenderFrameHost::FromID(render_process_id_, render_frame_id);
+  WebContents* web_contents = WebContents::FromRenderFrameHost(rfh);
+  DCHECK(web_contents);
+  GetContentClient()->browser()->RequestPermission(
+      content::PERMISSION_PROTECTED_MEDIA,
+      web_contents,
+      0,  // bridge id
+      security_origin,
+      // Only implemented for Android infobars which do not support
+      // user gestures.
+      true,
+      base::Bind(&BrowserCdmManager::CreateSessionIfPermitted,
+                 this,
+                 render_frame_id,
+                 cdm_id,
+                 session_id,
+                 content_type,
+                 init_data));
+}
+
 void BrowserCdmManager::CreateSessionIfPermitted(
     int render_frame_id,
     int cdm_id,