Make nesting/running states a RunLoop rather than a MessageLoop concept.

mojo/public/cpp/bindings/lib/connector.cc

Index: mojo/public/cpp/bindings/lib/connector.cc
diff --git a/mojo/public/cpp/bindings/lib/connector.cc b/mojo/public/cpp/bindings/lib/connector.cc
index d93e45ed938cd9455222aed5855af75998408ab7..c97b37d0215d8ca5a2967790f6e12ae29427d247 100644
--- a/mojo/public/cpp/bindings/lib/connector.cc
+++ b/mojo/public/cpp/bindings/lib/connector.cc
@@ -14,6 +14,7 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_local.h"
 #include "mojo/public/cpp/bindings/lib/may_auto_lock.h"
@@ -25,11 +26,10 @@ namespace mojo {
 namespace {
 
 // The NestingObserver for each thread. Note that this is always a
-// Connector::MessageLoopNestingObserver; we use the base type here because that
+// Connector::RunLoopNestingObserver; we use the base type here because that
 // subclass is private to Connector.
-base::LazyInstance<
-    base::ThreadLocalPointer<base::MessageLoop::NestingObserver>>::Leaky
-    g_tls_nesting_observer = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<base::ThreadLocalPointer<base::RunLoop::NestingObserver>>::
+    Leaky g_tls_nesting_observer = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
@@ -44,7 +44,7 @@ class Connector::ActiveDispatchTracker {
 
  private:
   const base::WeakPtr<Connector> connector_;
-  MessageLoopNestingObserver* const nesting_observer_;
+  RunLoopNestingObserver* const nesting_observer_;
   ActiveDispatchTracker* outer_tracker_ = nullptr;
   ActiveDispatchTracker* inner_tracker_ = nullptr;
 
@@ -53,40 +53,41 @@ class Connector::ActiveDispatchTracker {
 
 // Watches the MessageLoop on the current thread. Notifies the current chain of
 // ActiveDispatchTrackers when a nested message loop is started.
-class Connector::MessageLoopNestingObserver
-    : public base::MessageLoop::NestingObserver,
+class Connector::RunLoopNestingObserver
+    : public base::RunLoop::NestingObserver,
       public base::MessageLoop::DestructionObserver {
  public:
-  MessageLoopNestingObserver() {
-    base::MessageLoop::current()->AddNestingObserver(this);
+  RunLoopNestingObserver() {
+    base::RunLoop::AddNestingObserverOnCurrentThread(this);
     base::MessageLoop::current()->AddDestructionObserver(this);
   }
 
-  ~MessageLoopNestingObserver() override {}
+  ~RunLoopNestingObserver() override {}
 
-  // base::MessageLoop::NestingObserver:
-  void OnBeginNestedMessageLoop() override {
+  // base::RunLoop::NestingObserver:
+  void OnBeginNestedRunLoop() override {
     if (top_tracker_)
       top_tracker_->NotifyBeginNesting();
   }
 
   // base::MessageLoop::DestructionObserver:
   void WillDestroyCurrentMessageLoop() override {
-    base::MessageLoop::current()->RemoveNestingObserver(this);
+    base::RunLoop::RemoveNestingObserverOnCurrentThread(this);
     base::MessageLoop::current()->RemoveDestructionObserver(this);
     DCHECK_EQ(this, g_tls_nesting_observer.Get().Get());
     g_tls_nesting_observer.Get().Set(nullptr);
     delete this;
   }
 
-  static MessageLoopNestingObserver* GetForThread() {
+  static RunLoopNestingObserver* GetForThread() {
     if (!base::MessageLoop::current() ||
-        !base::MessageLoop::current()->nesting_allowed())
+        !base::RunLoop::IsNestingAllowedOnCurrentThread()) {
       return nullptr;
-    auto* observer = static_cast<MessageLoopNestingObserver*>(
+    }
+    auto* observer = static_cast<RunLoopNestingObserver*>(
         g_tls_nesting_observer.Get().Get());
     if (!observer) {
-      observer = new MessageLoopNestingObserver;
+      observer = new RunLoopNestingObserver;
       g_tls_nesting_observer.Get().Set(observer);
     }
     return observer;
@@ -97,7 +98,7 @@ class Connector::MessageLoopNestingObserver
 
   ActiveDispatchTracker* top_tracker_ = nullptr;
 
-  DISALLOW_COPY_AND_ASSIGN(MessageLoopNestingObserver);
+  DISALLOW_COPY_AND_ASSIGN(RunLoopNestingObserver);
 };
 
 Connector::ActiveDispatchTracker::ActiveDispatchTracker(
@@ -132,7 +133,7 @@ Connector::Connector(ScopedMessagePipeHandle message_pipe,
                      scoped_refptr<base::SingleThreadTaskRunner> runner)
     : message_pipe_(std::move(message_pipe)),
       task_runner_(std::move(runner)),
-      nesting_observer_(MessageLoopNestingObserver::GetForThread()),
+      nesting_observer_(RunLoopNestingObserver::GetForThread()),
       weak_factory_(this) {
   if (config == MULTI_THREADED_SEND)
     lock_.emplace();