Use the default dispatcher where possible for nested message loops.

Notable changes:
 * Add QuitNestedMessageLoop() to client::DispatcherClient, which can be used to
   terminate a nested loop started by RunWithDispatcher().
 * FirstRunDialog is no longer a MessagePumpDispatcher. The default dispatcher
   is used instead, and QuitNestedMessageLoop() is called to terminate the loop
   instead of returning POST_DISPATCH_QUIT_LOOP from the Dispatch() override.

This change was previously committed in r253723 and r254089, but reverted in
r253744 and r254095 because some interactive_ui_tests on windows bots failed on
SimpleMessageBoxViews related change. So this CL aims to reland that CL without
the change in SimpleMessageBoxViews for now.

BUG=342338
R=sky@chromium.org

Review URL: https://codereview.chromium.org/192743007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256093 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 20 insertions, 5 deletions

diff --git a/ash/accelerators/accelerator_dispatcher.cc b/ash/accelerators/accelerator_dispatcher.cc
index 0395ee7..91ea13b 100644
--- a/ash/accelerators/accelerator_dispatcher.cc
+++ b/ash/accelerators/accelerator_dispatcher.cc
@@ -70,7 +70,6 @@ AcceleratorDispatcher::AcceleratorDispatcher(
     aura::Window* associated_window)
     : nested_dispatcher_(nested_dispatcher),
       associated_window_(associated_window) {
-  DCHECK(nested_dispatcher_);
   associated_window_->AddObserver(this);
 }
 
@@ -121,10 +120,13 @@ uint32_t AcceleratorDispatcher::Dispatch(const base::NativeEvent& event) {
         return POST_DISPATCH_NONE;
     }
 
-    return nested_dispatcher_->Dispatch(key_event.native_event());
+    return nested_dispatcher_
+               ? nested_dispatcher_->Dispatch(key_event.native_event())
+               : POST_DISPATCH_PERFORM_DEFAULT;
   }
 
-  return nested_dispatcher_->Dispatch(event);
+  return nested_dispatcher_ ? nested_dispatcher_->Dispatch(event)
+                            : POST_DISPATCH_PERFORM_DEFAULT;
 }
 
 }  // namespace ash
diff --git a/ash/accelerators/accelerator_dispatcher.h b/ash/accelerators/accelerator_dispatcher.h
index a7ae40a..a46368c 100644
--- a/ash/accelerators/accelerator_dispatcher.h
+++ b/ash/accelerators/accelerator_dispatcher.h
@@ -15,8 +15,8 @@ namespace ash {
 // Dispatcher for handling accelerators from menu.
 //
 // Wraps a nested dispatcher to which control is passed if no accelerator key
-// has been pressed.
-// TODO(pkotwicz): Port AcceleratorDispatcher to mac.
+// has been pressed. If the nested dispatcher is NULL, then the control is
+// passed back to the default dispatcher.
 // TODO(pkotwicz): Add support for a |nested_dispatcher| which sends
 //  events to a system IME.
 class ASH_EXPORT AcceleratorDispatcher : public base::MessagePumpDispatcher,
diff --git a/ash/accelerators/nested_dispatcher_controller.cc b/ash/accelerators/nested_dispatcher_controller.cc
index c551e94..6977f07 100644
--- a/ash/accelerators/nested_dispatcher_controller.cc
+++ b/ash/accelerators/nested_dispatcher_controller.cc
@@ -6,6 +6,7 @@
 
 #include "ash/accelerators/accelerator_dispatcher.h"
 #include "ash/shell.h"
+#include "base/auto_reset.h"
 #include "base/run_loop.h"
 
 namespace ash {
@@ -27,7 +28,14 @@ void NestedDispatcherController::RunWithDispatcher(
   // TODO(jbates) crbug.com/134753 Find quitters of this RunLoop and have them
   //              use run_loop.QuitClosure().
   base::RunLoop run_loop(&dispatcher);
+  base::AutoReset<base::Closure> reset_closure(&quit_closure_,
+                                               run_loop.QuitClosure());
   run_loop.Run();
 }
 
+void NestedDispatcherController::QuitNestedMessageLoop() {
+  CHECK(!quit_closure_.is_null());
+  quit_closure_.Run();
+}
+
 }  // namespace ash
diff --git a/ash/accelerators/nested_dispatcher_controller.h b/ash/accelerators/nested_dispatcher_controller.h
index 958cbae..1f8b52e 100644
--- a/ash/accelerators/nested_dispatcher_controller.h
+++ b/ash/accelerators/nested_dispatcher_controller.h
@@ -6,6 +6,7 @@
 #define ASH_ACCELERATORS_NESTED_DISPATCHER_CONTROLLER_H_
 
 #include "ash/ash_export.h"
+#include "base/callback.h"
 #include "base/message_loop/message_loop.h"
 #include "ui/aura/client/dispatcher_client.h"
 #include "ui/aura/window.h"
@@ -22,10 +23,14 @@ class ASH_EXPORT NestedDispatcherController
   NestedDispatcherController();
   virtual ~NestedDispatcherController();
 
+  // aura::client::DispatcherClient:
   virtual void RunWithDispatcher(base::MessagePumpDispatcher* dispatcher,
                                  aura::Window* associated_window) OVERRIDE;
+  virtual void QuitNestedMessageLoop() OVERRIDE;
 
  private:
+  base::Closure quit_closure_;
+
   DISALLOW_COPY_AND_ASSIGN(NestedDispatcherController);
 };