diff --git a/buffet/commands/command_dictionary.cc b/buffet/commands/command_dictionary.cc
index 64f47c1..54753ad 100644
--- a/buffet/commands/command_dictionary.cc
+++ b/buffet/commands/command_dictionary.cc
@@ -5,10 +5,10 @@
 #include "buffet/commands/command_dictionary.h"
 
 #include <base/values.h>
+#include <chromeos/string_utils.h>
 
 #include "buffet/commands/command_definition.h"
 #include "buffet/commands/schema_constants.h"
-#include "buffet/string_utils.h"
 
 namespace buffet {
 
@@ -63,8 +63,8 @@
         return false;
       }
       // Construct the compound command name as "pkg_name.cmd_name".
-      std::string full_command_name = string_utils::Join('.', package_name,
-                                                         command_name);
+      std::string full_command_name = chromeos::string_utils::Join(
+          '.', package_name, command_name);
       // Get the "parameters" definition of the command and read it into
       // an object schema.
       const base::DictionaryValue* command_schema_def = nullptr;
@@ -158,7 +158,7 @@
       dict.reset();
       return dict;
     }
-    auto cmd_name_parts = string_utils::SplitAtFirst(pair.first, '.');
+    auto cmd_name_parts = chromeos::string_utils::SplitAtFirst(pair.first, '.');
     std::string package_name = cmd_name_parts.first;
     std::string command_name = cmd_name_parts.second;
     base::DictionaryValue* package = nullptr;
diff --git a/buffet/commands/command_queue_unittest.cc b/buffet/commands/command_queue_unittest.cc
index 2c0e01b..a9d5ad9 100644
--- a/buffet/commands/command_queue_unittest.cc
+++ b/buffet/commands/command_queue_unittest.cc
@@ -6,11 +6,11 @@
 #include <string>
 #include <vector>
 
+#include <chromeos/string_utils.h>
 #include <gtest/gtest.h>
 
 #include "buffet/commands/command_dispatch_interface.h"
 #include "buffet/commands/command_queue.h"
-#include "buffet/string_utils.h"
 
 namespace {
 
@@ -46,7 +46,7 @@
   // Get the comma-separated list of command IDs currently accumulated in the
   // command queue.
   std::string GetIDs() const {
-    using buffet::string_utils::Join;
+    using chromeos::string_utils::Join;
     return Join(',', std::vector<std::string>(ids_.begin(), ids_.end()));
   }
 
@@ -99,7 +99,7 @@
   std::string id1 = queue.Add(CreateDummyCommandInstance());
   std::string id2 = queue.Add(CreateDummyCommandInstance());
   std::set<std::string> ids{id1, id2};  // Make sure they are sorted properly.
-  std::string expected_set = buffet::string_utils::Join(
+  std::string expected_set = chromeos::string_utils::Join(
       ',', std::vector<std::string>(ids.begin(), ids.end()));
   EXPECT_EQ(expected_set, dispatch.GetIDs());
   queue.Remove(id1);
diff --git a/buffet/commands/prop_constraints.cc b/buffet/commands/prop_constraints.cc
index 210b254..c9008d2 100644
--- a/buffet/commands/prop_constraints.cc
+++ b/buffet/commands/prop_constraints.cc
@@ -5,7 +5,6 @@
 #include "buffet/commands/prop_constraints.h"
 #include "buffet/commands/prop_values.h"
 #include "buffet/commands/schema_constants.h"
-#include "buffet/string_utils.h"
 
 namespace buffet {
 
@@ -41,7 +40,8 @@
                                errors::commands::kOutOfRange,
                                "Value %s is invalid. Expected one of [%s]",
                                val.c_str(),
-                               string_utils::Join(',', values).c_str());
+                               chromeos::string_utils::Join(',',
+                                                            values).c_str());
   return false;
 }
 
diff --git a/buffet/commands/prop_constraints.h b/buffet/commands/prop_constraints.h
index 3aa6e8e..e765f44 100644
--- a/buffet/commands/prop_constraints.h
+++ b/buffet/commands/prop_constraints.h
@@ -12,11 +12,11 @@
 #include <base/basictypes.h>
 #include <base/values.h>
 #include <chromeos/error.h>
+#include <chromeos/string_utils.h>
 
 #include "buffet/commands/prop_values.h"
 #include "buffet/commands/schema_constants.h"
 #include "buffet/commands/schema_utils.h"
-#include "buffet/string_utils.h"
 
 namespace buffet {
 
@@ -138,8 +138,8 @@
     T v = value.GetValueAsAny().Get<T>();
     if (v < this->limit_.value)
       return this->ReportErrorLessThan(
-          error, string_utils::ToString(v),
-          string_utils::ToString(this->limit_.value));
+          error, chromeos::string_utils::ToString(v),
+          chromeos::string_utils::ToString(this->limit_.value));
     return true;
   }
 
@@ -175,8 +175,8 @@
     T v = value.GetValueAsAny().Get<T>();
     if (v > this->limit_.value)
       return this->ReportErrorGreaterThan(
-          error, string_utils::ToString(v),
-          string_utils::ToString(this->limit_.value));
+          error, chromeos::string_utils::ToString(v),
+          chromeos::string_utils::ToString(this->limit_.value));
     return true;
   }
 
@@ -282,7 +282,7 @@
   // Implementation of Constraint::Validate().
   bool Validate(const PropValue& value,
                 chromeos::ErrorPtr* error) const override {
-    using string_utils::ToString;
+    using chromeos::string_utils::ToString;
     T v = value.GetValueAsAny().Get<T>();
     for (const auto& item : set_.value) {
       if (CompareValue(v, item))
diff --git a/buffet/commands/prop_types.cc b/buffet/commands/prop_types.cc
index a3d7d6c..505dd5d 100644
--- a/buffet/commands/prop_types.cc
+++ b/buffet/commands/prop_types.cc
@@ -11,11 +11,11 @@
 #include <base/json/json_writer.h>
 #include <base/logging.h>
 #include <base/values.h>
+#include <chromeos/string_utils.h>
 
 #include "buffet/commands/object_schema.h"
 #include "buffet/commands/prop_values.h"
 #include "buffet/commands/schema_constants.h"
-#include "buffet/string_utils.h"
 
 namespace buffet {