Split fpdfsdk/fsdk_annothandler.h into individual classes.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index a4a3e8dd65e90d483d510eb1e56b54eaaaf11855..1969a4bc764d4f2e18f64aabb24a5f72cb5cfc3a 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -65,8 +65,12 @@ static_library("pdfium") {
     "fpdfsdk/cfx_systemhandler.cpp",
     "fpdfsdk/cfx_systemhandler.h",
     "fpdfsdk/cpdfsdk_annot.cpp",
+    "fpdfsdk/cpdfsdk_annothandlermgr.cpp",
+    "fpdfsdk/cpdfsdk_annotiterator.cpp",
     "fpdfsdk/cpdfsdk_baannot.cpp",
+    "fpdfsdk/cpdfsdk_bfannothandler.cpp",
     "fpdfsdk/cpdfsdk_datetime.cpp",
+    "fpdfsdk/cpdfsdk_xfaannothandler.cpp",
     "fpdfsdk/fpdf_dataavail.cpp",
     "fpdfsdk/fpdf_ext.cpp",
     "fpdfsdk/fpdf_flatten.cpp",
@@ -83,17 +87,20 @@ static_library("pdfium") {
     "fpdfsdk/fpdftext.cpp",
     "fpdfsdk/fpdfview.cpp",
     "fpdfsdk/fsdk_actionhandler.cpp",
-    "fpdfsdk/fsdk_annothandler.cpp",
     "fpdfsdk/fsdk_baseform.cpp",
     "fpdfsdk/fsdk_mgr.cpp",
     "fpdfsdk/fsdk_pauseadapter.cpp",
     "fpdfsdk/include/cpdfsdk_annot.h",
+    "fpdfsdk/include/cpdfsdk_annothandlermgr.h",
+    "fpdfsdk/include/cpdfsdk_annotiterator.h",
     "fpdfsdk/include/cpdfsdk_baannot.h",
+    "fpdfsdk/include/cpdfsdk_bfannothandler.h",
     "fpdfsdk/include/cpdfsdk_datetime.h",
+    "fpdfsdk/include/cpdfsdk_xfaannothandler.h",
     "fpdfsdk/include/fsdk_actionhandler.h",
-    "fpdfsdk/include/fsdk_annothandler.h",
     "fpdfsdk/include/fsdk_baseform.h",
     "fpdfsdk/include/fsdk_pauseadapter.h",
+    "fpdfsdk/include/ifpdfsdk_annothandler.h",
     "public/fpdf_dataavail.h",
     "public/fpdf_doc.h",
     "public/fpdf_edit.h",