Revert of Remove calls to MessageLoop::current() in content.

content/renderer/devtools/devtools_agent.cc

Index: content/renderer/devtools/devtools_agent.cc
diff --git a/content/renderer/devtools/devtools_agent.cc b/content/renderer/devtools/devtools_agent.cc
index b864e551d81bcf3be46625f89d7ff0304d193782..27b7c32d6b2193a75383d4516e5deccef8c31a03 100644
--- a/content/renderer/devtools/devtools_agent.cc
+++ b/content/renderer/devtools/devtools_agent.cc
@@ -11,9 +11,7 @@
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop/message_loop.h"
-#include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
-#include "base/threading/non_thread_safe.h"
 #include "base/trace_event/trace_event.h"
 #include "content/common/devtools_messages.h"
 #include "content/common/frame_messages.h"
@@ -44,25 +42,20 @@
 const size_t kMaxMessageChunkSize = IPC::Channel::kMaximumMessageSize / 4;
 const char kPageGetAppManifest[] = "Page.getAppManifest";
 
+
 class WebKitClientMessageLoopImpl
-    : public WebDevToolsAgentClient::WebKitClientMessageLoop,
-      public base::NonThreadSafe {
+    : public WebDevToolsAgentClient::WebKitClientMessageLoop {
  public:
-  WebKitClientMessageLoopImpl() { DCHECK(CalledOnValidThread()); }
-  ~WebKitClientMessageLoopImpl() override { DCHECK(CalledOnValidThread()); }
+  WebKitClientMessageLoopImpl() : message_loop_(base::MessageLoop::current()) {}
+  ~WebKitClientMessageLoopImpl() override { message_loop_ = NULL; }
   void run() override {
-    DCHECK(CalledOnValidThread());
-    base::MessageLoop::ScopedNestableTaskAllower allow(
-        base::MessageLoop::current());
-    run_loop_.Run();
-  }
-  void quitNow() override {
-    DCHECK(CalledOnValidThread());
-    run_loop_.Quit();
-  }
+    base::MessageLoop::ScopedNestableTaskAllower allow(message_loop_);
+    message_loop_->Run();
+  }
+  void quitNow() override { message_loop_->QuitNow(); }
 
  private:
-  base::RunLoop run_loop_;
+  base::MessageLoop* message_loop_;
 };
 
 typedef std::map<int, DevToolsAgent*> IdToAgentMap;