handler: Implement open as a pass-through function

When opening a blob id, handler finds a blobstore with matching
base id and calls its open function, passing down the path and open
flags.

Signed-off-by: Kun Yi <kunyi@google.com>
Change-Id: I6127b3c2b2c4752b5e094db61f12451089ccb20b
diff --git a/test/Makefile.am b/test/Makefile.am
index b80b6d2..5b3fe6c 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -10,6 +10,7 @@
 
 # Run all 'check' test programs
 check_PROGRAMS = \
+	handler_open_unittest \
 	handler_unittest
 TESTS = $(check_PROGRAMS)
 
@@ -17,3 +18,8 @@
 handler_unittest_LDADD = $(PHOSPHOR_LOGGING_LIBS) \
 	$(top_builddir)/handler.o
 handler_unittest_CXXFLAGS = $(PHOSPHOR_LOGGING_CFLAGS)
+
+handler_open_unittest_SOURCES = handler_open_unittest.cpp
+handler_open_unittest_LDADD = $(PHOSPHOR_LOGGING_LIBS) \
+	$(top_builddir)/handler.o
+handler_open_unittest_CXXFLAGS = $(PHOSPHOR_LOGGING_CFLAGS)