Wrapper class for annotation dictionary + CPDF_Form

Simple wrapper class for annotation + its path parsing form object. This
will be used in APIs for extracting and setting annotation paths.

Bug=pdfium:737

Change-Id: I2e8131672d087613213735295c6d01e377b956e7
Reviewed-on: https://pdfium-review.googlesource.com/6730
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
diff --git a/fpdfsdk/fpdfedit_embeddertest.cpp b/fpdfsdk/fpdfedit_embeddertest.cpp
index f7bade9..fcf7e39 100644
--- a/fpdfsdk/fpdfedit_embeddertest.cpp
+++ b/fpdfsdk/fpdfedit_embeddertest.cpp
@@ -900,8 +900,7 @@
   ASSERT_TRUE(page);
 
   // Add an underline annotation to the page without specifying its rectangle.
-  FPDF_ANNOTATION annot;
-  ASSERT_TRUE(FPDFPage_CreateAnnot(page, FPDF_ANNOT_UNDERLINE, &annot));
+  ASSERT_TRUE(FPDFPage_CreateAnnot(page, FPDF_ANNOT_UNDERLINE, nullptr));
 
   // FPDFPage_TransformAnnots() should run without errors when modifying
   // annotation rectangles.