Print out the error when loading an extension fails.

chrome/browser/extensions/installed_loader.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/extensions/installed_loader.h"
 
 #include "base/file_path.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
@@ skipping 124 matching lines @@
       base::ThreadRestrictions::ScopedAllowIO allow_io;
 
       std::string error;
       scoped_refptr<const Extension> extension(
           extension_file_util::LoadExtension(
               info->extension_path,
               info->extension_location,
               GetCreationFlags(info),
               &error));
 
-      if (extension.get()) {
-        extensions_info->at(i)->extension_manifest.reset(
-            static_cast<DictionaryValue*>(
-                extension->manifest()->value()->DeepCopy()));
-        should_write_prefs = true;
+      if (!extension.get()) {
+        extension_service_->
+            ReportExtensionLoadError(info->extension_path, error, false);
+        continue;
       }
+
+      extensions_info->at(i)->extension_manifest.reset(
+          static_cast<DictionaryValue*>(
+              extension->manifest()->value()->DeepCopy()));
+      should_write_prefs = true;
     }
   }
 
   for (size_t i = 0; i < extensions_info->size(); ++i) {
     Load(*extensions_info->at(i), should_write_prefs);
   }
 
   extension_service_->OnLoadedInstalledExtensions();
 
   // The histograms Extensions.ManifestReload* allow us to validate
@@ skipping 130 matching lines @@
   if (extension_prefs_->AllowFileAccess(info->extension_id))
     flags |= Extension::ALLOW_FILE_ACCESS;
   if (extension_prefs_->IsFromWebStore(info->extension_id))
     flags |= Extension::FROM_WEBSTORE;
   if (extension_prefs_->IsFromBookmark(info->extension_id))
     flags |= Extension::FROM_BOOKMARK;
   return flags;
 }
 
 }  // namespace extensions