Add Widevine signature files into Mac build

chrome/BUILD.gn

Index: chrome/BUILD.gn
diff --git a/chrome/BUILD.gn b/chrome/BUILD.gn
index 6b9f5c0b28a745b28f0ad9ccb8c4987fa695f51f..ad6057eb8d7aa1c0cb290e61c58fb190cc765ec1 100644
--- a/chrome/BUILD.gn
+++ b/chrome/BUILD.gn
@@ -649,6 +649,13 @@ if (is_win) {
       # non-component builds, will ensure the export symbol table is correct.
       ":verify_chrome_framework_order",
     ]
+
+    # Only official builds that include Widevine need the widevine
+    # signature file.
+    if (is_chrome_branded && enable_pepper_cdms) {
+      sources += [ "$root_out_dir/$chrome_framework_name.sig" ]
+      public_deps += [ ":sign_chrome_framework_for_widevine" ]
+    }
   }
 
   action("clean_up_old_versions") {
@@ -862,12 +869,25 @@ if (is_win) {
         ":widevine_cdm_library_copy",
         "//third_party/widevine/cdm:widevinecdmadapter",
       ]
+
+      # Signatures are only generated for official chrome.
+      if (is_chrome_branded) {
+        sources += [
+          "$root_out_dir/$widevine_cdm_path/widevinecdmadapter.plugin.sig",
+          "$root_out_dir/libwidevinecdm.dylib.sig",
+        ]
+        public_deps += [ ":sign_cdm_adapter_for_widevine" ]
+      }
     }
 
     copy("widevine_cdm_library_copy") {
       sources = [
         "$root_out_dir/$widevine_cdm_path/libwidevinecdm.dylib",
       ]
+      if (is_chrome_branded) {
+        sources +=
+            [ "$root_out_dir/$widevine_cdm_path/libwidevinecdm.dylib.sig" ]
+      }
       outputs = [
         "$root_out_dir/{{source_file_part}}",
       ]
@@ -887,6 +907,25 @@ if (is_win) {
         "//third_party/widevine/cdm:widevine_cdm_manifest",
       ]
     }
+
+    widevine_sign_file("sign_cdm_adapter_for_widevine") {
+      file = "$root_out_dir/$widevine_cdm_path/widevinecdmadapter.plugin"
+      deps = [
+        "//third_party/widevine/cdm:widevinecdmadapter",
+      ]
+    }
+
+    widevine_sign_file("sign_chrome_framework_for_widevine") {
+      file = "$root_out_dir/$chrome_framework_name.framework/"
+      if (defined(chrome_framework_version)) {
+        file += "Versions/$chrome_framework_version/"
+      }
+      file += "$chrome_framework_name"
+      signature_file = "$root_out_dir/$chrome_framework_name.sig"
+      deps = [
+        ":chrome_framework",
+      ]
+    }
   }
 
   group("widevine_cdm_library") {