Update CertVerifier to watch for the origin loop's destruction, so that

net/base/cert_verifier.cc

Index: net/base/cert_verifier.cc
diff --git a/net/base/cert_verifier.cc b/net/base/cert_verifier.cc
index 4e941335653adea573ae13ae3dadcb18ebed3c01..ed3d27a2183660457fb4310661973d8b80a5c67a 100644
--- a/net/base/cert_verifier.cc
+++ b/net/base/cert_verifier.cc
@@ -17,7 +17,9 @@
 namespace net {
 
 class CertVerifier::Request :
-    public base::RefCountedThreadSafe<CertVerifier::Request> {
+    public base::RefCountedThreadSafe<CertVerifier::Request,
+                                      CertVerifier::RequestTraits>,
+    public MessageLoop::DestructionObserver {
  public:
   Request(CertVerifier* verifier,
           X509Certificate* cert,
@@ -33,6 +35,7 @@ class CertVerifier::Request :
         callback_(callback),
         origin_loop_(MessageLoop::current()),
         error_(OK) {
+    origin_loop_->AddDestructionObserver(this);
   }
 
   void DoVerify() {
@@ -84,15 +87,42 @@ class CertVerifier::Request :
 
   void Cancel() {
     verifier_ = NULL;
+    AutoLock locked(origin_loop_lock_);
+    if (origin_loop_) {
+      origin_loop_->RemoveDestructionObserver(this);
+      origin_loop_ = NULL;
+    }
+  }
 
+  // MessageLoop::DestructionObserver override.
+  virtual void WillDestroyCurrentMessageLoop() {
+    LOG(ERROR) << "CertVerifier wasn't deleted before the thread was deleted.";
     AutoLock locked(origin_loop_lock_);
     origin_loop_ = NULL;
   }
 
  private:
   friend class base::RefCountedThreadSafe<CertVerifier::Request>;
+  friend class DeleteTask<CertVerifier::Request>;
+  friend struct CertVerifier::RequestTraits;
 
-  ~Request() {}
+  ~Request() {
+    Cancel();
+  }
+
+  // If we have an origin_loop_, the observer needs to be removed on that
+  // thread.  OnDestruct is called by RequestTraits to ensure this
+  // happens.
+  void OnDestruct() const {
+    {
+      AutoLock locked(origin_loop_lock_);
+      if (origin_loop_ && origin_loop_ != MessageLoop::current()) {
+        origin_loop_->DeleteSoon(FROM_HERE, this);
+        return;
+      }
+    }
+    delete this;
+  }
 
   // Set on the origin thread, read on the worker thread.
   scoped_refptr<X509Certificate> cert_;
@@ -106,7 +136,7 @@ class CertVerifier::Request :
   CompletionCallback* callback_;
 
   // Used to post ourselves onto the origin thread.
-  Lock origin_loop_lock_;
+  mutable Lock origin_loop_lock_;
   MessageLoop* origin_loop_;
 
   // Assigned on the worker thread, read on the origin thread.
@@ -114,6 +144,12 @@ class CertVerifier::Request :
   CertVerifyResult result_;
 };
 
+struct CertVerifier::RequestTraits {
+  static void Destruct(const CertVerifier::Request* request) {
+    request->OnDestruct();
+  }
+};
+
 //-----------------------------------------------------------------------------
 
 CertVerifier::CertVerifier() {