Moving extension code out of "components/" to avoid layering violations.

chrome/browser/renderer_context_menu/context_menu_content_type_platform_app.h

Index: chrome/browser/renderer_context_menu/context_menu_content_type_platform_app.h
diff --git a/chrome/browser/renderer_context_menu/context_menu_content_type_platform_app.h b/chrome/browser/renderer_context_menu/context_menu_content_type_platform_app.h
index 44389aa9b740b87354582f841c2db8b2db142cb2..087a3f7069119134ca6143b876e87efd9f3d3f01 100644
--- a/chrome/browser/renderer_context_menu/context_menu_content_type_platform_app.h
+++ b/chrome/browser/renderer_context_menu/context_menu_content_type_platform_app.h
@@ -7,6 +7,10 @@
 
 #include "components/renderer_context_menu/context_menu_content_type.h"
 
+namespace extensions {
+class Extension;
+}
+
 class ContextMenuContentTypePlatformApp : public ContextMenuContentType {
  public:
   ~ContextMenuContentTypePlatformApp() override;
@@ -18,6 +22,8 @@ class ContextMenuContentTypePlatformApp : public ContextMenuContentType {
   ContextMenuContentTypePlatformApp(content::WebContents* web_contents,
                                     const content::ContextMenuParams& params);
 
+  const extensions::Extension* GetExtension() const;
+
  private:
   friend class ContextMenuContentTypeFactory;