Don't delay creation of system URLRequestContext until first use

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 5bf834ad3917b3f93a9337726cec701d151a9a7e..3a7217b1306f3303067c0ec3edc3b73708415630 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -36,7 +36,6 @@
 class PrefProxyConfigTracker;
 class PrefService;
 class PrefRegistrySimple;
-class SystemURLRequestContextGetter;
 
 #if defined(OS_ANDROID)
 namespace chrome {
@@ -54,6 +53,10 @@ namespace certificate_transparency {
 class TreeStateTracker;
 }
 
+namespace chrome {
+class TestingIOThreadState;
+}
+
 namespace chrome_browser_net {
 class DnsProbeService;
 }
@@ -265,11 +268,8 @@ class IOThread : public content::BrowserThreadDelegate {
   bool PacHttpsUrlStrippingEnabled() const;
 
  private:
-  // Provide SystemURLRequestContextGetter with access to
-  // InitSystemRequestContext().
-  friend class SystemURLRequestContextGetter;
-
   friend class test::IOThreadPeer;
+  friend class chrome::TestingIOThreadState;
 
   // BrowserThreadDelegate implementation, runs on the IO thread.
   // This handles initialization and destruction of state that must
@@ -277,16 +277,6 @@ class IOThread : public content::BrowserThreadDelegate {
   void Init() override;
   void CleanUp() override;
 
-  // Global state must be initialized on the IO thread, then this
-  // method must be invoked on the UI thread.
-  void InitSystemRequestContext();
-
-  // Lazy initialization of system request context for
-  // SystemURLRequestContextGetter. To be called on IO thread only
-  // after global state has been initialized on the IO thread, and
-  // SystemRequestContext state has been initialized on the UI thread.
-  void InitSystemRequestContextOnIOThread();
-
   void CreateDefaultAuthHandlerFactory();
 
   // Returns an SSLConfigService instance.