Add EC and Firmware Versions to the Omaha Response.

This CL adds 2 additional utils methods to get the version for both the
fw and ec versions. I've added a unittest to verify these work and piped
in the values into the omaha response.

BUG=chromium:219871
TEST=Unittests + on device

Change-Id: Iadf70fff858988f52797d94bcdb062bb2482bbf3
Reviewed-on: https://gerrit.chromium.org/gerrit/49713
Commit-Queue: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
diff --git a/utils.h b/utils.h
index bc645d2..5193845 100644
--- a/utils.h
+++ b/utils.h
@@ -38,6 +38,16 @@
 // Returns the HWID or an empty string on error.
 std::string GetHardwareClass();
 
+// Returns the firmware version or an empty string if the system is not running
+// chrome os firmware.
+std::string GetFirmwareVersion();
+
+// Returns the ec version or an empty string if the system is not running a
+// custom chrome os ec. If input_line is not NULL, reads from this line,
+// otherwise polls the system for the input line. input_line should contain
+// fw_version=value.
+std::string GetECVersion(const char* input_line);
+
 // Writes the data passed to path. The file at path will be overwritten if it
 // exists. Returns true on success, false otherwise.
 bool WriteFile(const char* path, const char* data, int data_len);