Rename dictionary set and get methods

This Cl makes the Get and Set methods consistenly use {G|S}et<Type>For.

BUG=pdfium:596

Review-Url: https://codereview.chromium.org/2334323005
diff --git a/fpdfsdk/fpdfsave.cpp b/fpdfsdk/fpdfsave.cpp
index 81cc913..243ba2a 100644
--- a/fpdfsdk/fpdfsave.cpp
+++ b/fpdfsdk/fpdfsave.cpp
@@ -100,11 +100,11 @@
   if (!pRoot)
     return false;
 
-  CPDF_Dictionary* pAcroForm = pRoot->GetDictBy("AcroForm");
+  CPDF_Dictionary* pAcroForm = pRoot->GetDictFor("AcroForm");
   if (!pAcroForm)
     return false;
 
-  CPDF_Object* pXFA = pAcroForm->GetObjectBy("XFA");
+  CPDF_Object* pXFA = pAcroForm->GetObjectFor("XFA");
   if (!pXFA)
     return true;