Adds hook for content embedders to get media::BrowserCdm*.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 84dfb18bb10c07a1c72d524cc21a050f829f7a95..2b51eb9ed42986a4a14724990ab4fd0bf672cd9b 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -977,6 +977,14 @@ void RenderProcessHostImpl::SendUpdateValueState(unsigned int target,
   }
 }
 
+#if defined(ENABLE_BROWSER_CDMS)
+media::BrowserCdm* RenderProcessHostImpl::GetBrowserCdm(int render_frame_id,
+                                                        int cdm_id) const {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  return browser_cdm_manager_->GetCdm(render_frame_id, cdm_id);
+}
+#endif
+
 void RenderProcessHostImpl::AddRoute(
     int32 routing_id,
     IPC::Listener* listener) {