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: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605480}

chrome/browser/about_flags.cc

@@ -2202,9 +2202,11 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kSSLCommittedInterstitialsName,
      flag_descriptions::kSSLCommittedInterstitialsDescription, kOsAll,
      FEATURE_VALUE_TYPE(features::kSSLCommittedInterstitials)},
+#if defined(OS_ANDROID)
     {"enable-site-per-process", flag_descriptions::kStrictSiteIsolationName,
-     flag_descriptions::kStrictSiteIsolationDescription, kOsAll,
+     flag_descriptions::kStrictSiteIsolationDescription, kOsAndroid,
      SINGLE_VALUE_TYPE(switches::kSitePerProcess)},
+#endif
     {"site-isolation-trial-opt-out",
      flag_descriptions::kSiteIsolationOptOutName,
      flag_descriptions::kSiteIsolationOptOutDescription, kOsAll,

chrome/browser/flag_descriptions.cc

@@ -1736,27 +1736,29 @@ const char kSingleTabMode[] = "Single-tab mode";
 const char kSingleTabModeDescription[] =
     "Windows with a single tab receive a special, minimal visual treatment.";
 
+#if defined(OS_ANDROID)
 const char kStrictSiteIsolationName[] = "Strict site isolation";
 const char kStrictSiteIsolationDescription[] =
     "Security mode that enables site isolation for all sites (SitePerProcess). "
     "In this mode, each renderer process will contain pages from at most one "
-    "site, using out-of-process iframes when needed. NOTE: Site isolation is "
-    "enabled by default on desktop platforms regardless of how this flag is "
-    "set; see chrome://process-internals for whether it is currently enabled. "
+    "site, using out-of-process iframes when needed. "
+    "Check chrome://process-internals to see the current isolation mode. "
     "Setting this flag to 'Enabled' turns on site isolation regardless of the "
     "default. Here, 'Disabled' is a legacy value that actually means "
     "'Default,' in which case site isolation may be already enabled based on "
     "platform, enterprise policy, or field trial. See also "
     "#site-isolation-trial-opt-out for how to disable site isolation for "
     "testing.";
+#endif
 
 const char kSiteIsolationOptOutName[] = "Disable site isolation";
 const char kSiteIsolationOptOutDescription[] =
     "Disables site isolation "
     "(SitePerProcess, IsolateOrigins, etc). Intended for diagnosing bugs that "
     "may be due to out-of-process iframes. Opt-out has no effect if site "
-    "isolation is force-enabled via #enable-site-per-process or enterprise "
-    "policy. Caution: this disables important mitigations for the Spectre CPU "
+    "isolation is force-enabled using a command line switch or using an "
+    "enterprise policy. "
+    "Caution: this disables important mitigations for the Spectre CPU "
     "vulnerability affecting most computers.";
 const char kSiteIsolationOptOutChoiceDefault[] = "Default";
 const char kSiteIsolationOptOutChoiceOptOut[] = "Disabled (not recommended)";

chrome/browser/flag_descriptions.h

@@ -1048,8 +1048,10 @@ extern const char kSingleClickAutofillDescription[];
 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[];