Update all users of base::Version to explicitly specify the namespace, and clean up the header.

chrome/browser/extensions/webstore_installer.cc

Index: chrome/browser/extensions/webstore_installer.cc
diff --git a/chrome/browser/extensions/webstore_installer.cc b/chrome/browser/extensions/webstore_installer.cc
index 3bccff542e796664208621b30c313d49cf7ac020..50cd3fc1e8da2ec70a941aa25a61ef6457bf938c 100644
--- a/chrome/browser/extensions/webstore_installer.cc
+++ b/chrome/browser/extensions/webstore_installer.cc
@@ -356,7 +356,7 @@ void WebstoreInstaller::Observe(int type,
         CHECK_EQ(extension->id(), id_);
         ReportSuccess();
       } else {
-        const Version version_required(info.minimum_version);
+        const base::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
@@ -430,11 +430,11 @@ void WebstoreInstaller::OnDownloadStarted(
     scoped_ptr<Approval> approval = Approval::CreateForSharedModule(profile_);
     const SharedModuleInfo::ImportInfo& info = pending_modules_.front();
     approval->extension_id = info.extension_id;
-    const Version version_required(info.minimum_version);
+    const base::Version version_required(info.minimum_version);
 
     if (version_required.IsValid()) {
       approval->minimum_version.reset(
-          new Version(version_required));
+          new base::Version(version_required));
     }
     download_item_->SetUserData(kApprovalKey, approval.release());
   } else {