Add build configuration for experimental Windows GDI code.

BUG=409472

Review-Url: https://codereview.chromium.org/2193783002

BUILD.gn

diff --git a/BUILD.gn b/BUILD.gn
index 872baf7..f7a6007 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -30,6 +30,10 @@
   if (pdf_enable_xfa) {
     defines += [ "PDF_ENABLE_XFA" ]
   }
+
+  if (pdf_use_win32_gdi) {
+    defines += [ "PDFIUM_PRINT_TEXT_WITH_GDI" ]
+  }
 }
 
 config("pdfium_core_config") {

build_overrides/pdfium.gni

diff --git a/build_overrides/pdfium.gni b/build_overrides/pdfium.gni
index 246671b..f3cddb7 100644
--- a/build_overrides/pdfium.gni
+++ b/build_overrides/pdfium.gni
@@ -12,3 +12,6 @@
 
 # Build PDFium against skia (experimental) rather than agg.
 pdf_use_skia_override = false
+
+# Build PDFium either with or without experimental win32 GDI APIs.
+pdf_use_win32_gdi_override = false

pdfium.gni

diff --git a/pdfium.gni b/pdfium.gni
index 9e20f96..ede452f 100644
--- a/pdfium.gni
+++ b/pdfium.gni
@@ -20,6 +20,9 @@
   # Build PDFium against skia (experimental) rather than agg.
   pdf_use_skia = pdf_use_skia_override
 
+  # Build PDFium with or without experimental win32 GDI APIs.
+  pdf_use_win32_gdi = pdf_use_win32_gdi_override
+
   # Build PDFium standalone
   pdf_is_standalone = false
 }

pdfium.gyp

diff --git a/pdfium.gyp b/pdfium.gyp
index 3a3c71e..fe2d176 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -8,6 +8,7 @@
     'pdf_use_skia%': 0,
     'pdf_enable_v8%': 1,
     'pdf_enable_xfa%': 0, # Set to 1 by standalone.gypi in a standalone build.
+    'pdf_use_win32_gdi%': 0,
     'variables': {
       'clang_use_chrome_plugins': 1,
     },
@@ -44,6 +45,9 @@
       ['pdf_enable_xfa==1', {
         'defines': ['PDF_ENABLE_XFA'],
       }],
+      ['pdf_use_win32_gdi==1', {
+        'defines': ['PDFIUM_PRINT_TEXT_WITH_GDI'],
+      }],
       ['OS=="linux"', {
         'conditions': [
           ['target_arch=="x64"', {