Unblock roll of PDFium into chromium

Remove GN arg which was conflicting.

Change-Id: I5e4851eeb8696818c63772905dd95ce1641a5374
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/107270
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 5889ff2..62a57c9 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -222,42 +222,34 @@
     # May flag some issues when converting int to size_t.
     cflags += [ "-Wtautological-unsigned-zero-compare" ]
 
-    # Catch misuse of cppgc in XFA.
-    if (pdf_enable_xfa && clang_use_chrome_plugins) {
+    if (clang_use_chrome_plugins) {
+      # Catch misuse of C-style pointers.
       cflags += [
-        "-Xclang",
-        "-add-plugin",
-        "-Xclang",
-        "blink-gc-plugin",
-      ]
-    }
+        # TODO(tsepez): enable these tests.
+        #"-Xclang",
+        #"-plugin-arg-find-bad-constructs",
+        #"-Xclang",
+        #"check-raw-ptr-fields",
 
-    if (pdf_enable_unowned_ptr_exclusion) {
-      cflags += [
-        "-Xclang",
-        "-plugin-arg-find-bad-constructs",
-        "-Xclang",
-        "check-raw-ptr-fields",
+        #"-Xclang",
+        #"-plugin-arg-find-bad-constructs",
+        #"-Xclang",
+        #"raw-ptr-exclude-path=public",
 
-        "-Xclang",
-        "-plugin-arg-find-bad-constructs",
-        "-Xclang",
-        "raw-ptr-exclude-path=public/",
+        #"-Xclang",
+        #"-plugin-arg-find-bad-constructs",
+        #"-Xclang",
+        #"raw-ptr-exclude-path=testing",
 
-        "-Xclang",
-        "-plugin-arg-find-bad-constructs",
-        "-Xclang",
-        "raw-ptr-exclude-path=testing/",
+        #"-Xclang",
+        #"-plugin-arg-find-bad-constructs",
+        #"-Xclang",
+        #"raw-ptr-exclude-path=unittest",
 
-        "-Xclang",
-        "-plugin-arg-find-bad-constructs",
-        "-Xclang",
-        "raw-ptr-exclude-path=unittest",
-
-        "-Xclang",
-        "-plugin-arg-find-bad-constructs",
-        "-Xclang",
-        "raw-ptr-exclude-path=embeddertest",
+        #"-Xclang",
+        #"-plugin-arg-find-bad-constructs",
+        #"-Xclang",
+        #"raw-ptr-exclude-path=embeddertest",
 
         # TODO(tsepez): enforce raw_ref<> as well.
         # "-Xclang",
@@ -265,7 +257,19 @@
         # "-Xclang",
         # "check-raw-ref-fields",
       ]
-      defines += [ "PDF_ENABLE_UNOWNED_PTR_EXCLUSION" ]
+      defines += [
+        #"PDF_ENABLE_UNOWNED_PTR_EXCLUSION",
+      ]
+
+      # Catch misuse of cppgc in XFA.
+      if (pdf_enable_xfa) {
+        cflags += [
+          "-Xclang",
+          "-add-plugin",
+          "-Xclang",
+          "blink-gc-plugin",
+        ]
+      }
     }
   }
 
diff --git a/README.md b/README.md
index 657cfda..cf09278 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,11 @@
 
 By default, the entire project builds with C++17.
 
+By default, PDFium expects to build with a clang compiler that provides
+additional chrome plugins. To build against a vanilla one lacking these,
+one must set
+`clang_use_chrome_plugins = false`.
+
 When complete the arguments will be stored in `<directory>/args.gn`, and
 GN will automatically use the new arguments to generate build files.
 Should your files fail to generate, please double-check that you have set
diff --git a/build_overrides/pdfium.gni b/build_overrides/pdfium.gni
index 134dd01..b7dc9e0 100644
--- a/build_overrides/pdfium.gni
+++ b/build_overrides/pdfium.gni
@@ -9,10 +9,6 @@
 # Default: Use a bundled FreeType.
 pdf_bundle_freetype_override = true
 
-# Build PDFium with Chromium's raw_ptr restriction enforcing clang plugin.
-# Default: Do not enforce this restriction
-pdf_enable_unowned_ptr_exclusion_override = false
-
 # Build PDFium either with or without v8 support.
 # Default: With V8 support.
 pdf_enable_v8_override = true
diff --git a/pdfium.gni b/pdfium.gni
index f451397..9c6ae8d 100644
--- a/pdfium.gni
+++ b/pdfium.gni
@@ -18,9 +18,6 @@
   # Generate logging messages for click events that reach PDFium
   pdf_enable_click_logging = false
 
-  # Enforce chrome plugin raw_ptr restrictions.
-  pdf_enable_unowned_ptr_exclusion = pdf_enable_unowned_ptr_exclusion_override
-
   # Build PDFium either with or without v8 support.
   pdf_enable_v8 = pdf_enable_v8_override