Improve error message for failing code insertion on about:-URLs

extensions/renderer/programmatic_script_injector.cc

Index: extensions/renderer/programmatic_script_injector.cc
diff --git a/extensions/renderer/programmatic_script_injector.cc b/extensions/renderer/programmatic_script_injector.cc
index f393f9e213a299cf1244d467752264942bd426a6..7a74a2ae5c51d742b9c1253e68e7c4180dde60da 100644
--- a/extensions/renderer/programmatic_script_injector.cc
+++ b/extensions/renderer/programmatic_script_injector.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "base/values.h"
+#include "content/public/common/url_constants.h"
 #include "content/public/renderer/render_view.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/extension_messages.h"
@@ -118,8 +119,13 @@ void ProgrammaticScriptInjector::OnWillNotInject(InjectFailureReason reason) {
   std::string error;
   switch (reason) {
     case NOT_ALLOWED:
-      error = ErrorUtils::FormatErrorMessage(manifest_errors::kCannotAccessPage,
-                                             url_.spec());
+      if (url_.SchemeIs(url::kAboutScheme)) {
+        error = ErrorUtils::FormatErrorMessage(
+            manifest_errors::kCannotAccessAboutUrl, url_.spec());
+      } else {
+        error = ErrorUtils::FormatErrorMessage(
+            manifest_errors::kCannotAccessPage, url_.spec());
+      }
       break;
     case EXTENSION_REMOVED:  // no special error here.
     case WONT_INJECT: