Clean up some CFFL class headers.

- Consistently initialize data structures.
- Change #defines into an enum and document where the values came from.
- Remove unneeded forward declarations.

Change-Id: I6c8d181db3e43c4fdd8b5bdf549c6b9b118564f7
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/64975
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fpdfsdk/formfiller/cffl_combobox.cpp b/fpdfsdk/formfiller/cffl_combobox.cpp
index e4b45ef..588c50c 100644
--- a/fpdfsdk/formfiller/cffl_combobox.cpp
+++ b/fpdfsdk/formfiller/cffl_combobox.cpp
@@ -19,9 +19,6 @@
 CFFL_ComboBox::CFFL_ComboBox(CPDFSDK_FormFillEnvironment* pApp,
                              CPDFSDK_Widget* pWidget)
     : CFFL_TextObject(pApp, pWidget) {
-  m_State.nIndex = 0;
-  m_State.nStart = 0;
-  m_State.nEnd = 0;
 }
 
 CFFL_ComboBox::~CFFL_ComboBox() {
diff --git a/fpdfsdk/formfiller/cffl_combobox.h b/fpdfsdk/formfiller/cffl_combobox.h
index 680a179..250dba7 100644
--- a/fpdfsdk/formfiller/cffl_combobox.h
+++ b/fpdfsdk/formfiller/cffl_combobox.h
@@ -12,13 +12,12 @@
 #include "core/fxcrt/fx_string.h"
 #include "fpdfsdk/formfiller/cffl_textobject.h"
 
-class CBA_FontMap;
 class CPWL_ComboBox;
 
 struct FFL_ComboBoxState {
-  int nIndex;
-  int nStart;
-  int nEnd;
+  int nIndex = 0;
+  int nStart = 0;
+  int nEnd = 0;
   WideString sValue;
 };
 
diff --git a/fpdfsdk/formfiller/cffl_listbox.h b/fpdfsdk/formfiller/cffl_listbox.h
index 04138e6..7f39f5a 100644
--- a/fpdfsdk/formfiller/cffl_listbox.h
+++ b/fpdfsdk/formfiller/cffl_listbox.h
@@ -13,7 +13,6 @@
 
 #include "fpdfsdk/formfiller/cffl_textobject.h"
 
-class CBA_FontMap;
 class CPWL_ListBox;
 
 class CFFL_ListBox final : public CFFL_TextObject {
diff --git a/fpdfsdk/formfiller/cffl_textfield.cpp b/fpdfsdk/formfiller/cffl_textfield.cpp
index b53221f..c3cd365 100644
--- a/fpdfsdk/formfiller/cffl_textfield.cpp
+++ b/fpdfsdk/formfiller/cffl_textfield.cpp
@@ -15,6 +15,17 @@
 #include "public/fpdf_fwlevent.h"
 #include "third_party/base/ptr_util.h"
 
+namespace {
+
+// PDF 1.7 spec, Table 8.25
+enum Alignment {
+  kLeft = 0,
+  kCenter = 1,
+  kRight = 2,
+};
+
+}  // namespace
+
 CFFL_TextField::CFFL_TextField(CPDFSDK_FormFillEnvironment* pApp,
                                CPDFSDK_Widget* pWidget)
     : CFFL_TextObject(pApp, pWidget) {}
@@ -55,13 +66,13 @@
 
   switch (m_pWidget->GetAlignment()) {
     default:
-    case BF_ALIGN_LEFT:
+    case kLeft:
       cp.dwFlags |= PES_LEFT;
       break;
-    case BF_ALIGN_MIDDLE:
+    case kCenter:
       cp.dwFlags |= PES_MIDDLE;
       break;
-    case BF_ALIGN_RIGHT:
+    case kRight:
       cp.dwFlags |= PES_RIGHT;
       break;
   }
diff --git a/fpdfsdk/formfiller/cffl_textfield.h b/fpdfsdk/formfiller/cffl_textfield.h
index fb6e299..5941b42 100644
--- a/fpdfsdk/formfiller/cffl_textfield.h
+++ b/fpdfsdk/formfiller/cffl_textfield.h
@@ -11,18 +11,11 @@
 
 #include "fpdfsdk/formfiller/cffl_textobject.h"
 
-#define BF_ALIGN_LEFT 0
-#define BF_ALIGN_MIDDLE 1
-#define BF_ALIGN_RIGHT 2
-
-class CBA_FontMap;
 class CPWL_Edit;
 
 struct FFL_TextFieldState {
-  FFL_TextFieldState() : nStart(0), nEnd(0) {}
-
-  int nStart;
-  int nEnd;
+  int nStart = 0;
+  int nEnd = 0;
   WideString sValue;
 };