Revert 201955 "Allow multiple base::MessagePumpForUI instances t..."

trunk/src/base/message_pump_win.cc

Index: trunk/src/base/message_pump_win.cc
===================================================================
--- trunk/src/base/message_pump_win.cc	(revision 201972)
+++ trunk/src/base/message_pump_win.cc	(working copy)
@@ -9,6 +9,8 @@
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
+#include "base/process_util.h"
+#include "base/win/wrapped_window_proc.h"
 
 namespace {
 
@@ -23,13 +25,12 @@
 
 namespace base {
 
+static const wchar_t kWndClass[] = L"Chrome_MessagePumpWindow";
+
 // Message sent to get an additional time slice for pumping (processing) another
 // task (a series of such messages creates a continuous task pump).
 static const int kMsgHaveWork = WM_USER + 1;
 
-// Used by MessagePumpUI to wake up the thread and check any pending timers.
-static const int kTimerId = 1;
-
 //-----------------------------------------------------------------------------
 // MessagePumpWin public:
 
@@ -95,12 +96,14 @@
 // MessagePumpForUI public:
 
 MessagePumpForUI::MessagePumpForUI()
-    : message_filter_(new MessageFilter),
-      window_(new win::MessageWindow()) {
-  CHECK(window_->Create(this));
+    : instance_(NULL),
+      message_filter_(new MessageFilter) {
+  InitMessageWnd();
 }
 
 MessagePumpForUI::~MessagePumpForUI() {
+  DestroyWindow(message_hwnd_);
+  UnregisterClass(kWndClass, instance_);
 }
 
 void MessagePumpForUI::ScheduleWork() {
@@ -108,7 +111,8 @@
     return;  // Someone else continued the pumping.
 
   // Make sure the MessagePump does some work for us.
-  BOOL ret = PostMessage(window_->hwnd(), kMsgHaveWork, 0, 0);
+  BOOL ret = PostMessage(message_hwnd_, kMsgHaveWork,
+                         reinterpret_cast<WPARAM>(this), 0);
   if (ret)
     return;  // There was room in the Window Message queue.
 
@@ -155,7 +159,8 @@
 
   // Create a WM_TIMER event that will wake us up to check for any pending
   // timers (in case we are running within a nested, external sub-pump).
-  BOOL ret = SetTimer(window_->hwnd(), kTimerId, delay_msec, NULL);
+  BOOL ret = SetTimer(message_hwnd_, reinterpret_cast<UINT_PTR>(this),
+                      delay_msec, NULL);
   if (ret)
     return;
   // If we can't set timers, we are in big trouble... but cross our fingers for
@@ -192,23 +197,18 @@
 //-----------------------------------------------------------------------------
 // MessagePumpForUI private:
 
-bool MessagePumpForUI::HandleMessage(HWND hwnd,
-                                     UINT message,
-                                     WPARAM wparam,
-                                     LPARAM lparam,
-                                     LRESULT* result) {
+// static
+LRESULT CALLBACK MessagePumpForUI::WndProcThunk(
+    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
   switch (message) {
     case kMsgHaveWork:
-      HandleWorkMessage();
+      reinterpret_cast<MessagePumpForUI*>(wparam)->HandleWorkMessage();
       break;
-
     case WM_TIMER:
-      HandleTimerMessage();
+      reinterpret_cast<MessagePumpForUI*>(wparam)->HandleTimerMessage();
       break;
   }
-
-  // Do default processing for all messages.
-  return false;
+  return DefWindowProc(hwnd, message, wparam, lparam);
 }
 
 void MessagePumpForUI::DoRunLoop() {
@@ -249,7 +249,7 @@
     // don't want to disturb that timer if it is already in flight.  However,
     // if we did do all remaining delayed work, then lets kill the WM_TIMER.
     if (more_work_is_plausible && delayed_work_time_.is_null())
-      KillTimer(window_->hwnd(), kTimerId);
+      KillTimer(message_hwnd_, reinterpret_cast<UINT_PTR>(this));
     if (state_->should_quit)
       break;
 
@@ -267,6 +267,20 @@
   }
 }
 
+void MessagePumpForUI::InitMessageWnd() {
+  WNDCLASSEX wc = {0};
+  wc.cbSize = sizeof(wc);
+  wc.lpfnWndProc = base::win::WrappedWindowProc<WndProcThunk>;
+  wc.hInstance = base::GetModuleFromAddress(wc.lpfnWndProc);
+  wc.lpszClassName = kWndClass;
+  instance_ = wc.hInstance;
+  RegisterClassEx(&wc);
+
+  message_hwnd_ =
+      CreateWindow(kWndClass, 0, 0, 0, 0, 0, 0, HWND_MESSAGE, 0, instance_, 0);
+  DCHECK(message_hwnd_);
+}
+
 void MessagePumpForUI::WaitForWork() {
   // Wait until a message is available, up to the time needed by the timer
   // manager to fire the next set of timers.
@@ -324,7 +338,7 @@
 }
 
 void MessagePumpForUI::HandleTimerMessage() {
-  KillTimer(window_->hwnd(), kTimerId);
+  KillTimer(message_hwnd_, reinterpret_cast<UINT_PTR>(this));
 
   // If we are being called outside of the context of Run, then don't do
   // anything.  This could correspond to a MessageBox call or something of
@@ -368,7 +382,7 @@
   }
 
   // While running our main message pump, we discard kMsgHaveWork messages.
-  if (msg.message == kMsgHaveWork && msg.hwnd == window_->hwnd())
+  if (msg.message == kMsgHaveWork && msg.hwnd == message_hwnd_)
     return ProcessPumpReplacementMessage();
 
   if (CallMsgFilter(const_cast<MSG*>(&msg), kMessageFilterCode))
@@ -415,7 +429,7 @@
   }
 
   DCHECK(!have_message || kMsgHaveWork != msg.message ||
-         msg.hwnd != window_->hwnd());
+         msg.hwnd != message_hwnd_);
 
   // Since we discarded a kMsgHaveWork message, we must update the flag.
   int old_have_work = InterlockedExchange(&have_work_, 0);