Bug 1344629 - Part 6: Rewrite unnecessary uses of nsLiteralString. r=dbaron

There's an antipattern where nsLiteralString is used as an unnecessary intermediary in converting from CharT* to CharT*,
e.g. CallAFunctionThatTakesACharPointer(NS_LITERAL_CSTRING("foo").get());
or
NS_NAMED_LITERAL_STRING(foo, "abc");
CallAFunctionThatTakesACharPointer(foo.get());

This patch rewrites the callsites that can be trivially changed to use char*/char16_t*.

I'd somewhat like to remove nsTLiteralString::get() altogether, but in code that's less straightforward than these examples, get() is useful enough to keep.

MozReview-Commit-ID: Kh1rUziVllo

widget/windows/WindowsUIUtils.cpp

@@ -168,10 +168,8 @@ WindowsUIUtils::UpdateTabletModeState()
         if (mInTabletMode != oldTabletModeState) {
           nsCOMPtr<nsIObserverService> observerService =
             mozilla::services::GetObserverService();
-          NS_NAMED_LITERAL_STRING(tabletMode, "tablet-mode");
-          NS_NAMED_LITERAL_STRING(normalMode, "normal-mode");
           observerService->NotifyObservers(nullptr, "tablet-mode-change",
-            ((mInTabletMode == eTabletModeOn) ? tabletMode.get() : normalMode.get()));
+            ((mInTabletMode == eTabletModeOn) ? u"tablet-mode" : u"normal-mode"));
         }
       }
     }