win: Remove two exit-time destructors from pdf_child_init and enable...

win: Remove two exit-time destructors from pdf_child_init and enable -Wexit-time-destructors for chrome/child.

The PDF setup code patches up two GDI functions. There's no need
to undo that patching at process exit, so use a function-local static
base::NoDestructor<> instead of a global.

Bug: 404525
Change-Id: I9cb06b857a8b95ba5cbac74be60f8225fbb6f72a
Reviewed-on: https://chromium-review.googlesource.com/1231073Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592112}

chrome/child/BUILD.gn

@@ -10,10 +10,7 @@ static_library("child") {
     "v8_breakpad_support_win.h",
   ]
 
-  # TODO(thakis): Enable on Windows too, http://crbug.com/404525
-  if (!is_win) {
-    configs += [ "//build/config/compiler:wexit_time_destructors" ]
-  }
+  configs += [ "//build/config/compiler:wexit_time_destructors" ]
 
   deps = [
     "//base",

chrome/child/pdf_child_init.cc

@@ -7,6 +7,7 @@
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
+#include "base/no_destructor.h"
 #include "base/win/current_module.h"
 #include "base/win/iat_patch_function.h"
 #include "content/public/child/child_thread.h"
@@ -15,8 +16,6 @@
 namespace {
 
 #if defined(OS_WIN)
-base::win::IATPatchFunction g_iat_patch_createdca;
-
 HDC WINAPI CreateDCAPatch(LPCSTR driver_name,
                           LPCSTR device_name,
                           LPCSTR output,
@@ -37,7 +36,6 @@ typedef DWORD (WINAPI* GetFontDataPtr) (HDC hdc,
                                         DWORD length);
 GetFontDataPtr g_original_get_font_data = nullptr;
 
-base::win::IATPatchFunction g_iat_patch_get_font_data;
 
 DWORD WINAPI GetFontDataPatch(HDC hdc,
                               DWORD table,
@@ -66,15 +64,19 @@ DWORD WINAPI GetFontDataPatch(HDC hdc,
 void InitializePDF() {
 #if defined(OS_WIN)
   // Need to patch a few functions for font loading to work correctly. This can
-  // be removed once we switch PDF to use Skia.
+  // be removed once we switch PDF to use Skia
+  // (https://bugs.chromium.org/p/pdfium/issues/detail?id=11).
   HMODULE current_module = CURRENT_MODULE();
-  g_iat_patch_createdca.PatchFromModule(
-      current_module, "gdi32.dll", "CreateDCA",
-      reinterpret_cast<void*>(CreateDCAPatch));
-  g_iat_patch_get_font_data.PatchFromModule(
+
+  static base::NoDestructor<base::win::IATPatchFunction> patch_createdca;
+  patch_createdca->PatchFromModule(current_module, "gdi32.dll", "CreateDCA",
+                                   reinterpret_cast<void*>(CreateDCAPatch));
+
+  static base::NoDestructor<base::win::IATPatchFunction> patch_get_font_data;
+  patch_get_font_data->PatchFromModule(
       current_module, "gdi32.dll", "GetFontData",
       reinterpret_cast<void*>(GetFontDataPatch));
   g_original_get_font_data = reinterpret_cast<GetFontDataPtr>(
-      g_iat_patch_get_font_data.original_function());
+      patch_get_font_data->original_function());
 #endif  // defined(OS_WIN)
 }