Use base namespace for string16 in components and cloud_print.

cloud_print/common/win/cloud_print_utils.h

Index: cloud_print/common/win/cloud_print_utils.h
diff --git a/cloud_print/common/win/cloud_print_utils.h b/cloud_print/common/win/cloud_print_utils.h
index 7effa1b758cf878420649d5f595932f67416360c..bc9895c66c65a5f71fdff09bee09049f336516c5 100644
--- a/cloud_print/common/win/cloud_print_utils.h
+++ b/cloud_print/common/win/cloud_print_utils.h
@@ -15,14 +15,14 @@ namespace cloud_print {
 HRESULT GetLastHResult();
 
 // Convert an HRESULT to a localized string.
-string16 GetErrorMessage(HRESULT hr);
+base::string16 GetErrorMessage(HRESULT hr);
 
 // Retrieves a string from the string table of the module that contains the
 // calling code.
-string16 LoadLocalString(DWORD id);
+base::string16 LoadLocalString(DWORD id);
 
 // Sets registry value to notify Google Update that product was used.
-void SetGoogleUpdateUsage(const string16& product_id);
+void SetGoogleUpdateUsage(const base::string16& product_id);
 
 }  // namespace cloud_print