Don't fail component registration if the component on disk is corrupt.

chrome/browser/component_updater/default_component_installer.cc

 // 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.
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
@@ skipping 146 matching lines @@
         older_dirs.push_back(path);
       }
     } else {
       latest_dir = path;
       latest_version = version;
       found = true;
     }
   }
 
   if (found) {
-    current_version_ = latest_version;
-    // TODO(ddorwin): Remove these members and pass them directly to
-    // FinishRegistration().
-    base::ReadFileToString(latest_dir.AppendASCII("manifest.fingerprint"),
-                           &current_fingerprint_);
     current_manifest_ = ReadManifest(latest_dir);
-    if (!current_manifest_) {
+    if (current_manifest_) {
+      current_version_ = latest_version;
+      // TODO(ddorwin): Remove these members and pass them directly to
+      // FinishRegistration().
+      base::ReadFileToString(latest_dir.AppendASCII("manifest.fingerprint"),
+                             &current_fingerprint_);
+    } else {
+      // If the manifest can't be read, mark the directory for deletion and
+      // continue as if there were no versioned directories at all.
       DLOG(ERROR) << "Failed to read manifest for "
                   << installer_traits_->GetName() << " ("
                   << base_dir.MaybeAsASCII() << ").";
-      return;
+      older_dirs.push_back(latest_dir);
     }
   }
 
   // Remove older versions of the component. None should be in use during
   // browser startup.
   for (std::vector<base::FilePath>::iterator iter = older_dirs.begin();
        iter != older_dirs.end();
        ++iter) {
     base::DeleteFile(*iter, true);
   }
@@ skipping 31 matching lines @@
 
   if (current_version_.CompareTo(base::Version(kNullVersion)) > 0) {
     scoped_ptr<base::DictionaryValue> manifest_copy(
         current_manifest_->DeepCopy());
     installer_traits_->ComponentReady(
         current_version_, GetInstallDirectory(), manifest_copy.Pass());
   }
 }
 
 }  // namespace component_updater