chore: add OCR scaffolding to PDF Viewer (#38127)

shell/common/extensions/api/BUILD.gn

@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//electron/buildflags/buildflags.gni")
 import("//extensions/buildflags/buildflags.gni")
 import("//tools/json_schema_compiler/json_features.gni")
 import("//tools/json_schema_compiler/json_schema_api.gni")
@@ -41,6 +42,10 @@ generated_json_strings("generated_api_json_strings") {
     "tabs.json",
   ]
 
+  if (enable_pdf_viewer) {
+    sources += [ "pdf_viewer_private.idl" ]
+  }
+
   configs = [ "//build/config:precompiled_headers" ]
   bundle_name = "Electron"
   schema_include_rules = "extensions/common/api:extensions::api::%(namespace)s"
@@ -56,6 +61,11 @@ generated_types("generated_api_types") {
     "resources_private.idl",
     "tabs.json",
   ]
+
+  if (enable_pdf_viewer) {
+    sources += [ "pdf_viewer_private.idl" ]
+  }
+
   configs = [ "//build/config:precompiled_headers" ]
   schema_include_rules = "extensions/common/api:extensions::api::%(namespace)s"
 

shell/common/extensions/api/_api_features.json

@@ -28,6 +28,10 @@
     "channel": "stable",
     "matches": ["<all_urls>"]
   },
+  "pdfViewerPrivate": {
+    "dependencies": ["permission:pdfViewerPrivate"],
+    "contexts": ["blessed_extension"]
+  },
   "resourcesPrivate": [{
     "dependencies": ["permission:resourcesPrivate"],
     "contexts": ["blessed_extension"]

shell/common/extensions/api/_permission_features.json

@@ -6,6 +6,15 @@
     ],
     "location": "component"
   },
+  "pdfViewerPrivate": {
+    "channel": "stable",
+    "extension_types": [
+      "extension"
+    ],
+    "allowlist": [
+      "CBCC42ABED43A4B58FE3810E62AFFA010EB0349F"
+    ]
+  },
   "management": {
     "channel": "stable",
     "extension_types": [

shell/common/extensions/api/pdf_viewer_private.idl

@@ -0,0 +1,39 @@
+// Copyright 2022 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Use the <code>chrome.pdfViewerPrivate</code> API for specific browser
+// functionality that the PDF Viewer needs from outside the PDF plugin. This API
+// is exclusively for the PDF Viewer.
+namespace pdfViewerPrivate {
+  callback IsAllowedLocalFileAccessCallback = void(boolean result);
+  callback IsPdfOcrAlwaysActiveCallback = void(boolean result);
+  callback OnPdfOcrPrefSetCallback = void(boolean result);
+
+  interface Functions {
+    // Determines if the given URL should be allowed to access local files from
+    // the PDF Viewer. |callback|: Called with true if URL should be allowed to
+    // access local files from the PDF Viewer, false otherwise.
+    [supportsPromises] static void isAllowedLocalFileAccess(
+        DOMString url,
+        IsAllowedLocalFileAccessCallback callback);
+
+    // Determines if the preference for PDF OCR is set to run PDF OCR always.
+    // |callback|: Called with true if PDF OCR is set to be always active;
+    // false otherwise.
+    [supportsPromises] static void isPdfOcrAlwaysActive(
+        IsPdfOcrAlwaysActiveCallback callback);
+
+    // Sets a pref value for PDF OCR.
+    // |value|: The new value of the pref.
+    // |callback|: The callback for whether the pref was set or not.
+    [supportsPromises] static void setPdfOcrPref(
+        boolean value, OnPdfOcrPrefSetCallback callback);
+  };
+
+  interface Events {
+    // Fired when a pref value for PDF OCR has changed.
+    // |value| The pref value that changed.
+    static void onPdfOcrPrefChanged(boolean value);
+  };
+};