Revert of base: Remove using:: declaration from version.h header.

chrome/browser/extensions/webstore_installer.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/webstore_installer.h"
 
 #include <set>
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 400 matching lines @@
     download_item_->RemoveObserver(this);
     download_item_->Remove();
     download_item_ = NULL;
   }
   crx_installer_ = NULL;
 
   if (pending_modules_.empty()) {
     CHECK_EQ(extension->id(), id_);
     ReportSuccess();
   } else {
-    const base::Version version_required(info.minimum_version);
+    const Version version_required(info.minimum_version);
     if (version_required.IsValid() &&
         extension->version()->CompareTo(version_required) < 0) {
       // It should not happen, CrxInstaller will make sure the version is
       // equal or newer than version_required.
       ReportFailure(kDependencyNotFoundError,
                     FAILURE_REASON_DEPENDENCY_NOT_FOUND);
     } else if (!SharedModuleInfo::IsSharedModule(extension)) {
       // It should not happen, CrxInstaller will make sure it is a shared
       // module.
       ReportFailure(kDependencyNotSharedModuleError,
@@ skipping 51 matching lines @@
 
   DCHECK_EQ(content::DOWNLOAD_INTERRUPT_REASON_NONE, interrupt_reason);
   DCHECK(!pending_modules_.empty());
   download_item_ = item;
   download_item_->AddObserver(this);
   if (pending_modules_.size() > 1) {
     // We are downloading a shared module. We need create an approval for it.
     scoped_ptr<Approval> approval = Approval::CreateForSharedModule(profile_);
     const SharedModuleInfo::ImportInfo& info = pending_modules_.front();
     approval->extension_id = info.extension_id;
-    const base::Version version_required(info.minimum_version);
+    const Version version_required(info.minimum_version);
 
     if (version_required.IsValid()) {
-      approval->minimum_version.reset(new base::Version(version_required));
+      approval->minimum_version.reset(
+          new Version(version_required));
     }
     download_item_->SetUserData(kApprovalKey, approval.release());
   } else {
     // It is for the main module of the extension. We should use the provided
     // |approval_|.
     if (approval_)
       download_item_->SetUserData(kApprovalKey, approval_.release());
   }
 
   if (!download_started_) {
@@ skipping 275 matching lines @@
         1,
         kMaxSizeKb,
         kNumBuckets);
   }
   UMA_HISTOGRAM_BOOLEAN(
       "Extensions.WebstoreDownload.InterruptTotalSizeUnknown",
       total_bytes <= 0);
 }
 
 }  // namespace extensions