Allow compiling PDFium without V8.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index f048f9db3c45128c5e1e8b3fb9355afbda201150..0016d8fd3112cd3745ea2e58f62b0d4e2d1d8ebc 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -17,6 +17,7 @@ config("pdfium_config") {
   include_dirs = [ "third_party/freetype/include" ]
   defines = [
     "OPJ_STATIC",
+    "PDF_ENABLE_V8",
     "V8_DEPRECATION_WARNINGS",
     "_CRT_SECURE_NO_WARNINGS",
   ]
@@ -111,7 +112,6 @@ static_library("pdfium") {
     ":fxedit",
     ":fxge",
     ":javascript",
-    ":jsapi",
     ":pdfwindow",
   ]
 
@@ -671,25 +671,6 @@ static_library("javascript") {
     "fpdfsdk/src/javascript/resource.h",
     "fpdfsdk/src/javascript/util.cpp",
     "fpdfsdk/src/javascript/util.h",
-  ]
-
-  configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [
-    ":pdfium_config",
-    "//build/config/compiler:no_chromium_code",
-  ]
-  include_dirs = [
-    "//v8",
-    "//v8/include",
-  ]
-
-  public_deps = [
-    "//v8",
-  ]
-}
-
-static_library("jsapi") {
-  sources = [
     "fpdfsdk/include/jsapi/fxjs_v8.h",
     "fpdfsdk/src/jsapi/fxjs_v8.cpp",
   ]