Move enable extensions define to a build flag.

chrome/browser/site_details.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/site_details.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
+#include "extensions/features/features.h"
 #include "url/origin.h"
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 #endif
 
 using content::BrowserContext;
 using content::BrowserThread;
 using content::RenderFrameHost;
 using content::RenderProcessHost;
 using content::SiteInstance;
 using content::WebContents;
 
 namespace {
 
 bool ShouldIsolate(BrowserContext* browser_context,
                    const IsolationScenario& scenario,
                    const GURL& site) {
   switch (scenario.policy) {
     case ISOLATE_NOTHING:
       return false;
     case ISOLATE_ALL_SITES:
       return true;
     case ISOLATE_HTTPS_SITES:
       // Note: For estimation purposes "isolate https sites" is really
       // implemented as "isolate non-http sites". This means that, for example,
       // the New Tab Page gets counted as two processes under this policy, and
       // extensions are isolated as well.
       return !site.SchemeIs(url::kHttpScheme);
     case ISOLATE_EXTENSIONS: {
-#if !defined(ENABLE_EXTENSIONS)
+#if !BUILDFLAG(ENABLE_EXTENSIONS)
       return false;
 #else
       if (!site.SchemeIs(extensions::kExtensionScheme))
         return false;
       extensions::ExtensionRegistry* registry =
           extensions::ExtensionRegistry::Get(browser_context);
       const extensions::Extension* extension =
           registry->enabled_extensions().GetExtensionOrAppByURL(site);
       return extension && !extension->is_hosted_app();
 #endif
@@ skipping 229 matching lines @@
   UMA_HISTOGRAM_COUNTS_100(
       "SiteIsolation.IsolateExtensionsProcessCountLowerBound",
       process_count_lower_bound[ISOLATE_EXTENSIONS]);
   UMA_HISTOGRAM_COUNTS_100(
       "SiteIsolation.IsolateExtensionsProcessCountEstimate",
       process_count_estimate[ISOLATE_EXTENSIONS]);
   UMA_HISTOGRAM_COUNTS_100(
       "SiteIsolation.IsolateExtensionsTotalProcessCountEstimate",
       process_count_estimate[ISOLATE_EXTENSIONS] + non_renderer_process_count);
 }