Add a feature flag to honor JavaScript content settings in PDFs

Add |chrome_pdf::features::kPdfHonorJsContentSettings| and the
corresponding UI in chrome://flags for enabling whether JavaScript
content settings get honored in PDFs.

The flag does not do anything yet.

Bug: 696650
Change-Id: Icaf97474617ad56ebc93c2e419e90b12c5385aed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2203480
Commit-Queue: Daniel Hosseinian <[email protected]>
Reviewed-by: Tom Sepez <[email protected]>
Reviewed-by: Lei Zhang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#773482}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index a001474..6a17948 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -3848,6 +3848,11 @@
      flag_descriptions::kPdfFormSaveDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(chrome_pdf::features::kSaveEditedPDFForm)},
 
+    {"pdf-honor-js-content-settings",
+     flag_descriptions::kPdfHonorJsContentSettingsName,
+     flag_descriptions::kPdfHonorJsContentSettingsDescription, kOsDesktop,
+     FEATURE_VALUE_TYPE(chrome_pdf::features::kPdfHonorJsContentSettings)},
+
     {"pdf-two-up-view", flag_descriptions::kPdfTwoUpViewName,
      flag_descriptions::kPdfTwoUpViewDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(chrome_pdf::features::kPDFTwoUpView)},