Bug 1530419 - Move PROFILER_AUTO_THREAD_SLEEP into WinUtils::WaitForMessage from callers - r=mstange

Both `nsAppShell::ProcessNextNativeEvent()` and `MessagePumpForUI::WaitForWork()` have a `PROFILER_AUTO_THREAD_SLEEP` surrounding the `mozilla::widget::WinUtils::WaitForMessage()` call.
However inside `WaitForMessage()` the call to `PeekMessageW()` may trigger a sequence of events (because the system delivers pending messages) that end in the initialization of a new thread, which invokes `ReentrantMonitor::Wait()` where there is a `PROFILER_AUTO_THREAD_SLEEP`.

To avoid this recursion, this patch moves `PROFILER_AUTO_THREAD_SLEEP` from both callers into `WaitForMessage()` to only enclose the actual potentially-sleeping operation `::MsgWaitForMultipleObjectsEx()`.

Differential Revision: https://phabricator.services.mozilla.com/D72850

ipc/chromium/src/base/message_pump_win.cc

@@ -248,8 +248,6 @@ void MessagePumpForUI::WaitForWork() {
   if (delay < 0)  // Negative value means no timers waiting.
     delay = INFINITE;
 
-  AUTO_PROFILER_THREAD_SLEEP;
-
   mozilla::widget::WinUtils::WaitForMessage(delay);
 }
 

widget/windows/WinUtils.cpp

@@ -9,6 +9,7 @@
 #include <knownfolders.h>
 #include <winioctl.h>
 
+#include "GeckoProfiler.h"
 #include "gfxPlatform.h"
 #include "gfxUtils.h"
 #include "nsWindow.h"
@@ -736,8 +737,12 @@ void WinUtils::WaitForMessage(DWORD aTimeoutMs) {
     if (elapsed >= aTimeoutMs) {
       break;
     }
-    DWORD result = ::MsgWaitForMultipleObjectsEx(0, NULL, aTimeoutMs - elapsed,
-                                                 MOZ_QS_ALLEVENT, waitFlags);
+    DWORD result;
+    {
+      AUTO_PROFILER_THREAD_SLEEP;
+      result = ::MsgWaitForMultipleObjectsEx(0, NULL, aTimeoutMs - elapsed,
+                                             MOZ_QS_ALLEVENT, waitFlags);
+    }
     NS_WARNING_ASSERTION(result != WAIT_FAILED, "Wait failed");
     if (result == WAIT_TIMEOUT) {
       break;

widget/windows/nsAppShell.cpp

@@ -543,7 +543,6 @@ bool nsAppShell::ProcessNextNativeEvent(bool mayWait) {
       mozilla::BackgroundHangMonitor().NotifyWait();
       {
         AUTO_PROFILER_LABEL("nsAppShell::ProcessNextNativeEvent::Wait", IDLE);
-        AUTO_PROFILER_THREAD_SLEEP;
         WinUtils::WaitForMessage();
       }
     }