[Extensions] Clean up renderer channel-related code

extensions/browser/renderer_startup_helper.cc

Index: extensions/browser/renderer_startup_helper.cc
diff --git a/extensions/browser/renderer_startup_helper.cc b/extensions/browser/renderer_startup_helper.cc
index 4a9c961de65845fcda1b23856a59ee5ab11eb772..9f3c171d9deaad4410cf87fe3c024ca1fc7db34f 100644
--- a/extensions/browser/renderer_startup_helper.cc
+++ b/extensions/browser/renderer_startup_helper.cc
@@ -16,6 +16,7 @@
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/common/extensions_client.h"
+#include "extensions/common/features/feature_channel.h"
 #include "ui/base/webui/web_ui_util.h"
 
 using content::BrowserContext;
@@ -51,6 +52,10 @@ void RendererStartupHelper::Observe(
         new ExtensionMsg_SetActivityLoggingEnabled(activity_logging_enabled));
   }
 
+  // Extensions need to know the channel for API restrictions. Send the channel
+  // to all renderers, as the non-extension renderers may have content scripts.
+  process->Send(new ExtensionMsg_SetChannel(GetCurrentChannel()));
+
   // Platform apps need to know the system font.
   // TODO(dbeam): this is not the system font in all cases.
   process->Send(new ExtensionMsg_SetSystemFont(webui::GetFontFamily(),