wm: Change the DispatcherClient interface.

Instead of having RunWithDispatcher() to start a nested message-loop, and a
corresponding QuitNestedMessageLoop() to terminate it, have a DispatcherRunLoop
object that is similar to base::RunLoop for starting a nested message loop for
a specified DispatcherClient.

BUG=none
R=sky@chromium.org

Review URL: https://codereview.chromium.org/280483003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@273634 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 54 insertions, 2 deletions

diff --git a/ui/wm/public/dispatcher_client.cc b/ui/wm/public/dispatcher_client.cc
index cec4a8a..e3be7ca 100644
--- a/ui/wm/public/dispatcher_client.cc
+++ b/ui/wm/public/dispatcher_client.cc
@@ -4,6 +4,7 @@
 
 #include "ui/wm/public/dispatcher_client.h"
 
+#include "base/callback.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_property.h"
 
@@ -12,6 +13,28 @@ DECLARE_WINDOW_PROPERTY_TYPE(aura::client::DispatcherClient*);
 namespace aura {
 namespace client {
 
+DispatcherRunLoop::DispatcherRunLoop(DispatcherClient* client,
+                                     base::MessagePumpDispatcher* dispatcher) {
+  client->PrepareNestedLoopClosures(dispatcher, &run_closure_, &quit_closure_);
+}
+
+DispatcherRunLoop::~DispatcherRunLoop() {
+}
+
+void DispatcherRunLoop::Run() {
+  base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
+  base::MessageLoopForUI::ScopedNestableTaskAllower allow_nested(loop);
+  run_closure_.Run();
+}
+
+base::Closure DispatcherRunLoop::QuitClosure() {
+  return quit_closure_;
+}
+
+void DispatcherRunLoop::Quit() {
+  quit_closure_.Run();
+}
+
 DEFINE_LOCAL_WINDOW_PROPERTY_KEY(DispatcherClient*, kDispatcherClientKey, NULL);
 
 void SetDispatcherClient(Window* root_window, DispatcherClient* client) {
diff --git a/ui/wm/public/dispatcher_client.h b/ui/wm/public/dispatcher_client.h
index 9fd9c94..a301e92 100644
--- a/ui/wm/public/dispatcher_client.h
+++ b/ui/wm/public/dispatcher_client.h
@@ -5,6 +5,8 @@
 #ifndef UI_WM_PUBLIC_DISPATCHER_CLIENT_H_
 #define UI_WM_PUBLIC_DISPATCHER_CLIENT_H_
 
+#include "base/callback.h"
+#include "base/macros.h"
 #include "base/message_loop/message_pump_dispatcher.h"
 #include "ui/aura/aura_export.h"
 
@@ -12,12 +14,39 @@ namespace aura {
 class Window;
 namespace client {
 
+class DispatcherClient;
+
+// A base::RunLoop like object for running a nested message-loop with a
+// specified DispatcherClient and a MessagePumpDispatcher.
+class AURA_EXPORT DispatcherRunLoop {
+ public:
+  DispatcherRunLoop(DispatcherClient* client,
+                    base::MessagePumpDispatcher* dispatcher);
+  ~DispatcherRunLoop();
+
+  void Run();
+  base::Closure QuitClosure();
+  void Quit();
+
+ private:
+  base::Closure run_closure_;
+  base::Closure quit_closure_;
+
+  DISALLOW_COPY_AND_ASSIGN(DispatcherRunLoop);
+};
+
 // An interface implemented by an object which handles nested dispatchers.
 class AURA_EXPORT DispatcherClient {
  public:
-  virtual void RunWithDispatcher(base::MessagePumpDispatcher* dispatcher) = 0;
+  virtual ~DispatcherClient() {}
+
+ protected:
+  friend class DispatcherRunLoop;
 
-  virtual void QuitNestedMessageLoop() = 0;
+  virtual void PrepareNestedLoopClosures(
+      base::MessagePumpDispatcher* dispatcher,
+      base::Closure* run_closure,
+      base::Closure* quit_closure) = 0;
 };
 
 AURA_EXPORT void SetDispatcherClient(Window* root_window,