Implements HandleWatcher in terms of MessagePumpMojo

mojo/common/message_pump_mojo.h

Index: mojo/common/message_pump_mojo.h
diff --git a/mojo/common/message_pump_mojo.h b/mojo/common/message_pump_mojo.h
index 4eba660294630be80082c6c0fd5c558ca4b1ce66..003e0500a009def441228e9f290430248a17ae72 100644
--- a/mojo/common/message_pump_mojo.h
+++ b/mojo/common/message_pump_mojo.h
@@ -8,6 +8,7 @@
 #include <map>
 
 #include "base/message_loop/message_pump.h"
+#include "base/time/time.h"
 #include "mojo/common/mojo_common_export.h"
 #include "mojo/public/system/core.h"
 
@@ -24,12 +25,13 @@ class MOJO_COMMON_EXPORT MessagePumpMojo : public base::MessagePump {
 
   // Registers a MessagePumpMojoHandler for the specified handle. Only one
   // handler can be registered for a specified handle. If there is an existing
-  // handler registered it is clobbered and silently removed.
-  // The handler is notified either when the handle is ready, or when it becomes
-  // invalid. If the handle becomes invalid the handler is removed and notified.
+  // handler already registered the existing handler is notified it was removed
+  // (MOJO_RESULT_CANCELLED).  If the handle becomes invalid the handler is
+  // removed and notified.
   void AddHandler(MessagePumpMojoHandler* handler,
                   MojoHandle handle,
-                  MojoWaitFlags wait_flags);
+                  MojoWaitFlags wait_flags,
+                  base::TimeTicks deadline);
 
   void RemoveHandler(MojoHandle handle);
 
@@ -51,6 +53,7 @@ class MOJO_COMMON_EXPORT MessagePumpMojo : public base::MessagePump {
 
     MessagePumpMojoHandler* handler;
     MojoWaitFlags wait_flags;
+    base::TimeTicks deadline;
   };
 
   typedef std::map<MojoHandle, Handler> HandleToHandler;
@@ -67,6 +70,9 @@ class MOJO_COMMON_EXPORT MessagePumpMojo : public base::MessagePump {
 
   WaitState GetWaitState() const;
 
+  // Returns the deadline for the call to MojoWaitMany().
+  MojoDeadline GetDeadlineForWait() const;
+
   // If non-NULL we're running (inside Run()). Member is reference to value on
   // stack.
   RunState* run_state_;