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/cpdfsdk_annothandlermgr.cpp b/fpdfsdk/cpdfsdk_annothandlermgr.cpp
index 443ee05..f808b84 100644
--- a/fpdfsdk/cpdfsdk_annothandlermgr.cpp
+++ b/fpdfsdk/cpdfsdk_annothandlermgr.cpp
@@ -63,8 +63,8 @@
   CPDF_Annot* pPDFAnnot = pAnnot->GetPDFAnnot();
 
   CPDFSDK_DateTime curTime;
-  pPDFAnnot->GetAnnotDict()->SetAtString("M", curTime.ToPDFDateTimeString());
-  pPDFAnnot->GetAnnotDict()->SetAtNumber("F", 0);
+  pPDFAnnot->GetAnnotDict()->SetStringFor("M", curTime.ToPDFDateTimeString());
+  pPDFAnnot->GetAnnotDict()->SetNumberFor("F", 0);
 
   GetAnnotHandler(pAnnot)->OnCreate(pAnnot);
 }