Adds a feature flag for PDF OCR

Inaccessible PDFs will be made accessible via optical character recognition.
More info in:
https://docs.google.com/document/d/1Xe1BBncEddGz8DYYnGdTHI0cwhJ_3BvfELCQY6T1rBw/edit?usp=sharing

AX-Relnotes: n/a.
Change-Id: I3cec0af8a9a51bf3f26ccfec48ab833c5a8852f7
Bug: 1248380
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3497057
Commit-Queue: Nektarios Paisios <[email protected]>
Auto-Submit: Nektarios Paisios <[email protected]>
Reviewed-by: Ramin Halavati <[email protected]>
Commit-Queue: Ramin Halavati <[email protected]>
Cr-Commit-Position: refs/heads/main@{#976594}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 17870f74..744d3d4 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -2037,6 +2037,11 @@
 const char kPasswordScriptsFetchingDescription[] =
     "Fetches scripts for password change flows.";
 
+const char kPdfOcrName[] = "Performs OCR on inaccessible PDFs";
+const char kPdfOcrDescription[] =
+    "Enables a feature whereby inaccessible (i.e. untagged) PDFs are made "
+    "accessible using an optical character recognition service.";
+
 const char kPdfXfaFormsName[] = "PDF XFA support";
 const char kPdfXfaFormsDescription[] =
     "Enables support for XFA forms in PDFs. "