ifdef extensions code in BrowserProcess, IOThread, and ChromeNetworkDelegate.

chrome/browser/net/chrome_network_delegate.cc

Index: chrome/browser/net/chrome_network_delegate.cc
diff --git a/chrome/browser/net/chrome_network_delegate.cc b/chrome/browser/net/chrome_network_delegate.cc
index 4e81a7bd4a102768eda9b363b662cf17e70c37b6..a7d81e5a9cece514d0f14bc5e25364972e4ec9ad 100644
--- a/chrome/browser/net/chrome_network_delegate.cc
+++ b/chrome/browser/net/chrome_network_delegate.cc
@@ -42,7 +42,6 @@
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_request_info.h"
-#include "extensions/common/constants.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
@@ -72,6 +71,10 @@
 #include "components/policy/core/browser/url_blacklist_manager.h"
 #endif
 
+#if defined(ENABLE_EXTENSIONS)
+#include "extensions/common/constants.h"
+#endif
+
 using content::BrowserThread;
 using content::RenderViewHost;
 using content::ResourceRequestInfo;
@@ -85,9 +88,11 @@ bool ChromeNetworkDelegate::g_allow_file_access_ = false;
 bool ChromeNetworkDelegate::g_allow_file_access_ = true;
 #endif
 
+#if defined(ENABLE_EXTENSIONS)
 // This remains false unless the --disable-extensions-http-throttling
 // flag is passed to the browser.
 bool ChromeNetworkDelegate::g_never_throttle_requests_ = false;
+#endif
 
 namespace {
 
@@ -338,9 +343,11 @@ void ChromeNetworkDelegate::SetEnableClientHints() {
 }
 
 // static
+#if defined(ENABLE_EXTENSIONS)
 void ChromeNetworkDelegate::NeverThrottleRequests() {
   g_never_throttle_requests_ = true;
 }
+#endif

[Ryan Sleevi, 2014/07/16 20:23:44]

Doesn't seem strictly necessary to #ifdef dance this out.

[Lei Zhang, 2014/07/18 01:34:24]

All the throttle code here exists to support
--disable-extensions-http-throttling

 
 // static
 void ChromeNetworkDelegate::InitializePrefsOnUIThread(
@@ -789,10 +796,14 @@ bool ChromeNetworkDelegate::OnCanAccessFile(const net::URLRequest& request,
 
 bool ChromeNetworkDelegate::OnCanThrottleRequest(
     const net::URLRequest& request) const {
+#if defined(ENABLE_EXTENSIONS)
   if (g_never_throttle_requests_)
     return false;
   return request.first_party_for_cookies().scheme() ==
       extensions::kExtensionScheme;
+#else
+  return false;
+#endif
 }
 
 bool ChromeNetworkDelegate::OnCanEnablePrivacyMode(