Remove chrome://flags/#enable-site-per-process on desktop platforms

site-per-process has shipped on desktop platforms in M67.
Therefore, chrome://flags/#enable-site-per-process is not needed on
desktop platforms (since the default already is to enable
site-per-process).

Bug: 901522
Change-Id: I0d0bceb3706453683362ae4c7efa41d78a9104d8
Reviewed-on: https://chromium-review.googlesource.com/c/1316649
Commit-Queue: Ɓukasz Anforowicz <[email protected]>
Reviewed-by: Charlie Reis <[email protected]>
Reviewed-by: Alex Moshchuk <[email protected]>
Cr-Commit-Position: refs/heads/master@{#605480}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 308e162..93682ac 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1048,8 +1048,10 @@
 extern const char kSingleTabMode[];
 extern const char kSingleTabModeDescription[];
 
+#if defined(OS_ANDROID)
 extern const char kStrictSiteIsolationName[];
 extern const char kStrictSiteIsolationDescription[];
+#endif
 
 extern const char kSiteIsolationOptOutName[];
 extern const char kSiteIsolationOptOutDescription[];