Use SolarMutexGuard directly

Change-Id: Ica2736fd9e249bfa88cfd8fd094af83deadf7737
loplugin:passstringbyref

Change-Id: If08dab3956da5c0ee90d6a788f6f34a936e792d7
loplugin:passstringbyref

Change-Id: I0cbb49b29f0b1ee69f342d14d4560924e7bc5d11
libstdc++ abs vs std::abs confusion (-Werror,-Wabsolute-value)

Change-Id: I55fdcdfb25a2d6456eff044eb4af8fa00905d6e8