Avoid parsing the webstore base url so much.

extensions/test/test_extensions_client.h

Index: extensions/test/test_extensions_client.h
diff --git a/extensions/test/test_extensions_client.h b/extensions/test/test_extensions_client.h
index bc64e56409362a8a71235cd63da9509d85c54451..190042bed7921ff7065212c8af2ad1036f513667 100644
--- a/extensions/test/test_extensions_client.h
+++ b/extensions/test/test_extensions_client.h
@@ -49,7 +49,7 @@ class TestExtensionsClient : public ExtensionsClient {
   base::StringPiece GetAPISchema(const std::string& name) const override;
   bool ShouldSuppressFatalErrors() const override;
   void RecordDidSuppressFatalError() override;
-  std::string GetWebstoreBaseURL() const override;
+  const GURL& GetWebstoreBaseURL() const override;
   const GURL& GetWebstoreUpdateURL() const override;
   bool IsBlacklistUpdateURL(const GURL& url) const override;
   std::set<base::FilePath> GetBrowserImagePaths(
@@ -63,6 +63,7 @@ class TestExtensionsClient : public ExtensionsClient {
 
   std::set<BrowserImagePathsFilter*> browser_image_filters_;
 
+  const GURL webstore_base_url_;
   const GURL webstore_update_url_;
 
   DISALLOW_COPY_AND_ASSIGN(TestExtensionsClient);