Revert 213906 "base: Re-apply WeakPtr support for SequencedWorke..."

trunk/src/base/sequence_checker.h

Index: trunk/src/base/sequence_checker.h
===================================================================
--- trunk/src/base/sequence_checker.h	(revision 213937)
+++ trunk/src/base/sequence_checker.h	(working copy)
@@ -28,11 +28,12 @@
 // the right version for your build configuration.
 class SequenceCheckerDoNothing {
  public:
-  bool CalledOnValidSequencedThread() const {
+  bool CalledOnValidSequence() const {
     return true;
   }
 
-  void DetachFromSequence() {}
+  void ChangeSequence(
+      const scoped_refptr<SequencedTaskRunner>& sequenced_task_runner) {}
 };
 
 // SequenceChecker is a helper class used to help verify that some
@@ -43,6 +44,10 @@
 // Example:
 // class MyClass {
 //  public:
+//   explicit MyClass(
+//       const scoped_refptr<SequencedTaskRunner>& sequenced_task_runner)
+//       : sequence_checker_(sequenced_task_runner) {}
+//
 //   void Foo() {
 //     DCHECK(sequence_checker_.CalledOnValidSequence());
 //     ... (do stuff) ...
@@ -55,9 +60,16 @@
 // In Release mode, CalledOnValidSequence will always return true.
 #if ENABLE_SEQUENCE_CHECKER
 class SequenceChecker : public SequenceCheckerImpl {
+ public:
+  explicit SequenceChecker(
+      const scoped_refptr<SequencedTaskRunner>& sequenced_task_runner)
+      : SequenceCheckerImpl(sequenced_task_runner) {}
 };
 #else
 class SequenceChecker : public SequenceCheckerDoNothing {
+ public:
+  explicit SequenceChecker(
+      const scoped_refptr<SequencedTaskRunner>& sequenced_task_runner) {}
 };
 #endif  // ENABLE_SEQUENCE_CHECKER