Bug 580165 - Clean up dead code related to missing screen managers in widget. r=jimm

--HG--
extra : rebase_source : e472caf15d50a835ce06ad761f72d130371d442a

widget/windows/nsWindow.cpp

@@ -1834,42 +1834,31 @@ NS_METHOD nsWindow::ConstrainPosition(bool aAllowSlop,
   RECT screenRect;
 
   nsCOMPtr<nsIScreenManager> screenmgr = do_GetService(sScreenManagerContractID);
-  if (screenmgr) {
-    nsCOMPtr<nsIScreen> screen;
-    int32_t left, top, width, height;
+  if (!screenmgr) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  nsCOMPtr<nsIScreen> screen;
+  int32_t left, top, width, height;
 
-    screenmgr->ScreenForRect(*aX, *aY, logWidth, logHeight,
-                             getter_AddRefs(screen));
-    if (screen) {
-      if (mSizeMode != nsSizeMode_Fullscreen) {
-        // For normalized windows, use the desktop work area.
-        screen->GetAvailRectDisplayPix(&left, &top, &width, &height);
-      } else {
-        // For full screen windows, use the desktop.
-        screen->GetRectDisplayPix(&left, &top, &width, &height);
-      }
-      screenRect.left = left;
-      screenRect.right = left + width;
-      screenRect.top = top;
-      screenRect.bottom = top + height;
+  screenmgr->ScreenForRect(*aX, *aY, logWidth, logHeight,
+                           getter_AddRefs(screen));
+  if (mSizeMode != nsSizeMode_Fullscreen) {
+    // For normalized windows, use the desktop work area.
+    nsresult rv = screen->GetAvailRectDisplayPix(&left, &top, &width, &height);
+    if (NS_FAILED(rv)) {
+      return rv;
     }
   } else {
-    if (mWnd) {
-      HDC dc = ::GetDC(mWnd);
-      if (dc) {
-        if (::GetDeviceCaps(dc, TECHNOLOGY) == DT_RASDISPLAY) {
-          if (mSizeMode != nsSizeMode_Fullscreen) {
-            ::SystemParametersInfo(SPI_GETWORKAREA, 0, &screenRect, 0);
-          } else {
-            screenRect.left = screenRect.top = 0;
-            screenRect.right = GetSystemMetrics(SM_CXFULLSCREEN);
-            screenRect.bottom = GetSystemMetrics(SM_CYFULLSCREEN);
-          }
-        }
-        ::ReleaseDC(mWnd, dc);
-      }
+    // For full screen windows, use the desktop.
+    nsresult rv = screen->GetRectDisplayPix(&left, &top, &width, &height);
+    if (NS_FAILED(rv)) {
+      return rv;
     }
   }
+  screenRect.left = left;
+  screenRect.right = left + width;
+  screenRect.top = top;
+  screenRect.bottom = top + height;
 
   if (aAllowSlop) {
     if (*aX < screenRect.left - logWidth + kWindowPositionSlop)