Consistently use namespaced base::Version in extensions code.

chrome/browser/extensions/updater/local_extension_cache.cc

Index: chrome/browser/extensions/updater/local_extension_cache.cc
diff --git a/chrome/browser/extensions/updater/local_extension_cache.cc b/chrome/browser/extensions/updater/local_extension_cache.cc
index 28f9b65d28ea96c02a26a066389e250e3192f383..05e9c98d95e7143066b0c5881ddde4dc61222beb 100644
--- a/chrome/browser/extensions/updater/local_extension_cache.cc
+++ b/chrome/browser/extensions/updater/local_extension_cache.cc
@@ -132,8 +132,8 @@ bool LocalExtensionCache::NewerOrSame(const CacheMap::iterator& entry,
                                       const std::string& version,
                                       const std::string& expected_hash,
                                       int* compare) {
-  Version new_version(version);
-  Version prev_version(entry->second.version);
+  base::Version new_version(version);
+  base::Version prev_version(entry->second.version);
   int cmp = new_version.CompareTo(prev_version);
 
   if (compare)
@@ -156,7 +156,7 @@ void LocalExtensionCache::PutExtension(const std::string& id,
     return;
   }
 
-  Version version_validator(version);
+  base::Version version_validator(version);
   if (!version_validator.IsValid()) {
     LOG(ERROR) << "Extension " << id << " has bad version " << version;
     callback.Run(file_path, true);
@@ -442,7 +442,7 @@ void LocalExtensionCache::BackendCheckCacheContentsInternal(
       id.clear();
     }
 
-    if (!Version(version).IsValid()) {
+    if (!base::Version(version).IsValid()) {
       LOG(ERROR) << "Bad extension version in cache: " << version;
       version.clear();
     }