Warn when extensions suggest conflicting download filenames

chrome/browser/extensions/extension_warning_set.cc

Index: chrome/browser/extensions/extension_warning_set.cc
diff --git a/chrome/browser/extensions/extension_warning_set.cc b/chrome/browser/extensions/extension_warning_set.cc
index 662e09c46c261f4a622b898a223916e1d760dd0e..67e90a34db3c53421398b8d7def85928ec8fc1e8 100644
--- a/chrome/browser/extensions/extension_warning_set.cc
+++ b/chrome/browser/extensions/extension_warning_set.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/extensions/extension_warning_set.h"
 
+#include "base/files/file_path.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/common/extensions/extension.h"
@@ -157,6 +158,24 @@ ExtensionWarning ExtensionWarning::CreateRepeatedCacheFlushesWarning(
       message_parameters);
 }
 
+// static
+ExtensionWarning ExtensionWarning::CreateDownloadFilenameConflictWarning(
+    const std::string& losing_extension_id,
+    const std::string& winning_extension_id,
+    const base::FilePath& losing_filename,
+    const base::FilePath& winning_filename) {
+  std::vector<std::string> message_parameters;
+  message_parameters.push_back(UTF16ToUTF8(losing_filename.LossyDisplayName()));
+  message_parameters.push_back(kTranslate + winning_extension_id);
+  message_parameters.push_back(UTF16ToUTF8(
+      winning_filename.LossyDisplayName()));
+  return ExtensionWarning(
+      kDownloadFilenameConflict,
+      losing_extension_id,
+      IDS_EXTENSION_WARNINGS_DOWNLOAD_FILENAME_CONFLICT,
+      message_parameters);
+}
+
 std::string ExtensionWarning::GetLocalizedMessage(
     const ExtensionSet* extensions) const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));