Bug 1068946 - Disable jsapi-tests for b2g emulators; r=RyanVM

--HG--
extra : rebase_source : 29e8e591e834d40f1804402788f0f5490e7d48a4

testing/b2g_cppunittest_manifest.txt

@@ -1,4 +1,5 @@
 # This is just a list of tests to skip, one test per line
+jsapi-tests                         # Bug 1068946
 TestPLDHash                         # Bug 1038197
 TestTXMgr                           # Bug 919595
 TestPlainTextSerializer             # Bug 919599