Deprecate NonThreadSafe in net/ in favor of SequenceChecker/ThreadChecker.

net/url_request/url_request_context.h

Index: net/url_request/url_request_context.h
diff --git a/net/url_request/url_request_context.h b/net/url_request/url_request_context.h
index 206b01059971c7fb906723599c16146afe158b2b..5a8ea66b7f9db304f67d3f21c6a821eb29802523 100644
--- a/net/url_request/url_request_context.h
+++ b/net/url_request/url_request_context.h
@@ -15,7 +15,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "net/base/net_export.h"
 #include "net/base/request_priority.h"
@@ -60,8 +60,7 @@ class URLRequestThrottlerManager;
 // URLRequestContext rather than creating a new one, as guaranteeing that the
 // URLRequestContext is destroyed before its members can be difficult.
 class NET_EXPORT URLRequestContext
-    : NON_EXPORTED_BASE(public base::NonThreadSafe),
-      public base::trace_event::MemoryDumpProvider {
+    : public base::trace_event::MemoryDumpProvider {
  public:
   URLRequestContext();
   ~URLRequestContext() override;
@@ -281,6 +280,10 @@ class NET_EXPORT URLRequestContext
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
+  void AssertCalledOnValidSequence() const {
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  }
+
  private:
   // ---------------------------------------------------------------------------
   // Important: When adding any new members below, consider whether they need to
@@ -333,6 +336,8 @@ class NET_EXPORT URLRequestContext
   // |this| and are not yet destroyed. This doesn't need to be in CopyFrom.
   mutable size_t largest_outstanding_requests_count_seen_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(URLRequestContext);
 };