[Extensions] Isolate ExtensionFunction results_ and error_

chrome/browser/extensions/chrome_extension_function.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSION_FUNCTION_H_
 #define CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSION_FUNCTION_H_
 
 #include "chrome/browser/extensions/chrome_extension_function_details.h"
 #include "extensions/browser/extension_function.h"
 
@@ skipping 36 matching lines @@
   // This method can return NULL if there is no matching browser, which can
   // happen if only incognito windows are open, or early in startup or shutdown
   // shutdown when there are no active windows.
   //
   // TODO(stevenjb): Replace this with GetExtensionWindowController().
   Browser* GetCurrentBrowser();
 
   // Same as above but uses WindowControllerList instead of BrowserList.
   extensions::WindowController* GetExtensionWindowController();
 
-  // Gets the "current" web contents if any. If there is no associated web
-  // contents then defaults to the foremost one.
+  // ExtensionFunction:
   content::WebContents* GetAssociatedWebContents() override;
+  void SetError(const std::string& error) override;
+  const std::string& GetError() const override;
+
+ protected:
+  ~ChromeUIThreadExtensionFunction() override;
 
   // Responds with success/failure. |results_| or |error_| should be set
   // accordingly.
   void SendResponse(bool success);
 
- protected:
-  ~ChromeUIThreadExtensionFunction() override;
+  // Sets a single Value as the results of the function.
+  void SetResult(std::unique_ptr<base::Value> result);
+
+  // Sets multiple Values as the results of the function.
+  void SetResultList(std::unique_ptr<base::ListValue> results);
+
+  std::unique_ptr<base::ListValue> results_;
+  std::string error_;

[lazyboy, 2016/09/30 01:16:05]

I'm finding this very hard to grok, can we use different name for these?
Probably an ugly name that suggests that this is temporary workaround (also
citing the bug# in comment) until RespondFoo only exclusively sets them.

[Devlin, 2016/09/30 18:29:09]

We can't name these something different, because existing Chrome* extension
function implementations directly access them (as "error_" and "results_").  The
main goal of this CL is to ensure that, as we convert to and write new extension
functions, we don't add new uses of these, but for now we need to keep the
current ones.

I've added a comment to that effect.

 
  private:
   ChromeExtensionFunctionDetails chrome_details_;
 };
 
 // A chrome specific analog to AsyncExtensionFunction. This has access to a
 // chrome Profile.
 //
 // DEPRECATED: Please consider inherting UIThreadExtensionFunction or
 // AsyncExtensionFunction directly. Then if you need access to Chrome details,
@@ skipping 40 matching lines @@
   static bool ValidationFailure(ChromeSyncExtensionFunction* function);
 
  private:
   // If you're hitting a compile error here due to "final" - great! You're doing
   // the right thing, you just need to extend ChromeUIThreadExtensionFunction
   // instead of ChromeSyncExtensionFunction.
   ResponseAction Run() final;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSION_FUNCTION_H_