Add function for getting supported H264 level from max resolution and fps

webrtc/common_video/h264/profile_level_id.h

Index: webrtc/common_video/h264/profile_level_id.h
diff --git a/webrtc/common_video/h264/profile_level_id.h b/webrtc/common_video/h264/profile_level_id.h
index c7aeff9f0143e6657883af99ecbf9486f447d84b..a4757f64e822670101926f5c75df2772a6e4d8ed 100644
--- a/webrtc/common_video/h264/profile_level_id.h
+++ b/webrtc/common_video/h264/profile_level_id.h
@@ -61,6 +61,10 @@ struct ProfileLevelId {
 // profile level id.
 rtc::Optional<ProfileLevelId> ParseProfileLevelId(const char* str);
 
+// Given the maximum supported frame size (in pixels) and fps, return the
+// highest H264 level the encoder/decoder is guaranteed to support.
+Level SupportedLevel(int max_frame_pixel_count, int max_fps);
+
 // Returns canonical string representation as three hex bytes of the profile
 // level id, or returns empty string for invalid profile level id.
 std::string ProfileLevelIdToString(const ProfileLevelId& profile_level_id);