Add DesktopFrame rotation functions

webrtc/modules/desktop_capture/rgba_color.cc

Index: webrtc/modules/desktop_capture/rgba_color.cc
diff --git a/webrtc/modules/desktop_capture/rgba_color.cc b/webrtc/modules/desktop_capture/rgba_color.cc
index 6d91de4275cd6b00c8c1c6e2c23dca55e7ef1397..e97b151d16a1f7fe2574c119ae8ac57fb6551c25 100644
--- a/webrtc/modules/desktop_capture/rgba_color.cc
+++ b/webrtc/modules/desktop_capture/rgba_color.cc
@@ -41,6 +41,8 @@ RgbaColor::RgbaColor(const uint8_t* bgra)
 RgbaColor::RgbaColor(uint32_t bgra)
     : RgbaColor(reinterpret_cast<uint8_t*>(&bgra)) {}
 
+RgbaColor::RgbaColor(int bgra) : RgbaColor(static_cast<uint32_t>(bgra)) {}
+
 bool RgbaColor::operator==(const RgbaColor& right) const {
   return blue == right.blue && green == right.green && red == right.red &&
          AlphaEquals(alpha, right.alpha);