Add UnloadExtension method

This CL adds a method to unload a previously loaded
extension.

Bug: b/73383411
Test: None
Change-Id: Id9f801c5c0296ba9748bfbd4417797f7f4eddb6d
Reviewed-on: https://chromium-review.googlesource.com/1070457Reviewed-by: Alex Sakhartchouk <alexst@chromium.org>
Commit-Queue: Randy Rossi <rmrossi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561610}

chromecast/browser/extensions/cast_extension_system.cc

@@ -133,6 +133,11 @@ const Extension* CastExtensionSystem::LoadExtension(
   return extension.get();
 }
 
+void CastExtensionSystem::UnloadExtension(const std::string& extension_id,
+                                          UnloadedExtensionReason reason) {
+  extension_registrar_->RemoveExtension(extension_id, reason);
+}
+
 void CastExtensionSystem::PostLoadExtension(
     const scoped_refptr<extensions::Extension>& extension) {
   extension_registrar_->AddExtension(extension);

chromecast/browser/extensions/cast_extension_system.h

@@ -41,6 +41,10 @@ class CastExtensionSystem : public ExtensionSystem,
   // Load an extension from the contents of a manifest file.
   const Extension* LoadExtensionByManifest(const std::string& manifest);
 
+  // Unload an extension.
+  void UnloadExtension(const std::string& extension_id,
+                       UnloadedExtensionReason reason);
+
   // Loads an unpacked platform app from a directory. Returns the extension on
   // success, or nullptr otherwise.
   // Currently this just calls LoadExtension, as apps are not loaded differently