Make static const char* arrays more const.

Change-Id: I87b5e6cefe973b82b4868e56fc5285c95c53a12b
Reviewed-on: https://pdfium-review.googlesource.com/12550
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
diff --git a/core/fpdfapi/parser/cpdf_object_unittest.cpp b/core/fpdfapi/parser/cpdf_object_unittest.cpp
index 169e0f1..770c718 100644
--- a/core/fpdfapi/parser/cpdf_object_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_object_unittest.cpp
@@ -697,8 +697,9 @@
 }
 
 TEST(PDFArrayTest, AddStringAndName) {
-  const char* vals[] = {"",        "a", "ehjhRIOYTTFdfcdnv",  "122323",
-                        "$#%^&**", " ", "This is a test.\r\n"};
+  static constexpr const char* vals[] = {
+      "",        "a", "ehjhRIOYTTFdfcdnv",  "122323",
+      "$#%^&**", " ", "This is a test.\r\n"};
   auto string_array = pdfium::MakeUnique<CPDF_Array>();
   auto name_array = pdfium::MakeUnique<CPDF_Array>();
   for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
diff --git a/core/fpdfdoc/cpdf_aaction.cpp b/core/fpdfdoc/cpdf_aaction.cpp
index 033bf03..fd29b52 100644
--- a/core/fpdfdoc/cpdf_aaction.cpp
+++ b/core/fpdfdoc/cpdf_aaction.cpp
@@ -8,9 +8,13 @@
 
 namespace {
 
-const char* g_sAATypes[] = {"E",  "X",  "D",  "U",  "Fo", "Bl", "PO", "PC",
-                            "PV", "PI", "O",  "C",  "K",  "F",  "V",  "C",
-                            "WC", "WS", "DS", "WP", "DP", ""};
+constexpr const char* g_sAATypes[] = {"E",  "X",  "D",  "U",  "Fo", "Bl", "PO",
+                                      "PC", "PV", "PI", "O",  "C",  "K",  "F",
+                                      "V",  "C",  "WC", "WS", "DS", "WP", "DP"};
+
+// |g_sAATypes| should have as many elements as enum AActionType.
+static_assert(FX_ArraySize(g_sAATypes) == CPDF_AAction::NumberOfActions,
+              "g_sAATypes count mismatch");
 
 }  // namespace
 
diff --git a/core/fpdfdoc/cpdf_aaction.h b/core/fpdfdoc/cpdf_aaction.h
index b2b691f..bacf179 100644
--- a/core/fpdfdoc/cpdf_aaction.h
+++ b/core/fpdfdoc/cpdf_aaction.h
@@ -34,7 +34,8 @@
     SaveDocument,
     DocumentSaved,
     PrintDocument,
-    DocumentPrinted
+    DocumentPrinted,
+    NumberOfActions  // Must be last.
   };
 
   CPDF_AAction();
diff --git a/fpdfsdk/cpdfsdk_widget.cpp b/fpdfsdk/cpdfsdk_widget.cpp
index e21ce73..60a4d52 100644
--- a/fpdfsdk/cpdfsdk_widget.cpp
+++ b/fpdfsdk/cpdfsdk_widget.cpp
@@ -164,11 +164,8 @@
       eEventType = XFA_EVENT_Exit;
       break;
     case CPDF_AAction::PageOpen:
-      break;
     case CPDF_AAction::PageClose:
-      break;
     case CPDF_AAction::PageVisible:
-      break;
     case CPDF_AAction::PageInvisible:
       break;
     case CPDF_AAction::KeyStroke:
@@ -188,6 +185,9 @@
     case CPDF_AAction::PrintDocument:
     case CPDF_AAction::DocumentPrinted:
       break;
+    case CPDF_AAction::NumberOfActions:
+      NOTREACHED();
+      break;
   }
 
   return eEventType;
diff --git a/xfa/fgas/font/cfgas_fontmgr.cpp b/xfa/fgas/font/cfgas_fontmgr.cpp
index 4b395c9..9cb772e 100644
--- a/xfa/fgas/font/cfgas_fontmgr.cpp
+++ b/xfa/fgas/font/cfgas_fontmgr.cpp
@@ -443,7 +443,7 @@
 
 namespace {
 
-const char* g_FontFolders[] = {
+constexpr const char* g_FontFolders[] = {
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_LINUX_
     "/usr/share/fonts", "/usr/share/X11/fonts/Type1",
     "/usr/share/X11/fonts/TTF", "/usr/local/share/fonts",