Drop -Iv8 flag from pdfium build

We converted the <v8.h> includes to "v8/include/v8.h" some revs back,
so we need not explicitly tell the compiler to look there.

Change-Id: Id71f1bad81a969eebf418c9d97b32864ea78480b
Reviewed-on: https://pdfium-review.googlesource.com/26251
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 821472f..b6a031a 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -260,10 +260,6 @@
       "//v8",
       "//v8:v8_libplatform",
     ]
-    include_dirs += [
-      "//v8",
-      "//v8/include",
-    ]
     configs += [ "//v8:external_startup_data" ]
   }
   configs += [ ":pdfium_core_config" ]
@@ -1284,10 +1280,6 @@
       "//v8:v8_libplatform",
     ]
     configs += [ "//v8:external_startup_data" ]
-    include_dirs = [
-      "//v8",
-      "//v8/include",
-    ]
     public_deps = [
       "//v8",
     ]
@@ -2964,10 +2956,6 @@
       "fxjs/cjs_publicmethods_unittest.cpp",
       "fxjs/cjs_util_unittest.cpp",
     ]
-    include_dirs += [
-      "//v8",
-      "//v8/include",
-    ]
     deps += [ ":fxjs" ]
     configs += [ "//v8:external_startup_data" ]
   }