Special case the gallery to not show the scary download roadblock.

chrome/common/extensions/extension_constants.h

Index: chrome/common/extensions/extension_constants.h
diff --git a/chrome/common/extensions/extension_constants.h b/chrome/common/extensions/extension_constants.h
index c8a717afc104f3ebc81dbb5b918f271ea358e34c..8d2500a6d47f2d21a756bee76cc3fecba42107c1 100644
--- a/chrome/common/extensions/extension_constants.h
+++ b/chrome/common/extensions/extension_constants.h
@@ -130,4 +130,16 @@ namespace extension_manifest_errors {
   extern const char* kInvalidOptionsPage;
 }  // namespace extension_manifest_errors
 
+namespace extension_urls {
+  // The greatest common prefixes of the main extensions gallery's browse and
+  // download URLs.
+  extern const char* kGalleryBrowsePrefix;
+  extern const char* kGalleryDownloadPrefix;
+
+  // Same thing for the "minigallery". The minigallery is the temporary static
+  // themes gallery that we put up when we launched themes.
+  extern const char* kMiniGalleryBrowsePrefix;
+  extern const char* kMiniGalleryDownloadPrefix;
+}  // namespace extension_urls
+
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_