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

components/component_updater/component_updater_service_unittest.cc

Index: components/component_updater/component_updater_service_unittest.cc
diff --git a/components/component_updater/component_updater_service_unittest.cc b/components/component_updater/component_updater_service_unittest.cc
index c66103ec8e3df4ed0cc611a2815c252a3ba7dc83..c44c63b7c1482c3efde1bb0c6d43c337b379c141 100644
--- a/components/component_updater/component_updater_service_unittest.cc
+++ b/components/component_updater/component_updater_service_unittest.cc
@@ -236,12 +236,12 @@
 
   CrxComponent crx_component1;
   crx_component1.pk_hash.assign(abag_hash, abag_hash + arraysize(abag_hash));
-  crx_component1.version = base::Version("1.0");
+  crx_component1.version = Version("1.0");
   crx_component1.installer = installer;
 
   CrxComponent crx_component2;
   crx_component2.pk_hash.assign(jebg_hash, jebg_hash + arraysize(jebg_hash));
-  crx_component2.version = base::Version("0.9");
+  crx_component2.version = Version("0.9");
   crx_component2.installer = installer;
 
   // Quit after two update checks have fired.
@@ -294,7 +294,7 @@
   using update_client::jebg_hash;
   CrxComponent crx_component;
   crx_component.pk_hash.assign(jebg_hash, jebg_hash + arraysize(jebg_hash));
-  crx_component.version = base::Version("0.9");
+  crx_component.version = Version("0.9");
   crx_component.installer = installer;
 
   LoopHandler loop_handler(1, quit_closure());
@@ -338,7 +338,7 @@
   using update_client::jebg_hash;
   CrxComponent crx_component;
   crx_component.pk_hash.assign(jebg_hash, jebg_hash + arraysize(jebg_hash));
-  crx_component.version = base::Version("0.9");
+  crx_component.version = Version("0.9");
   crx_component.installer = installer;
 
   LoopHandler loop_handler(1, quit_closure());