Add watch dog timer to OEMCrypto L3

Merge from Widevine repo of http://go/wvgerrit/33540

This code adds a watchdog timer to the level 3 initialization.  If
initialization does not finish within 5 seconds, the process will
abort, printing a small amount of debugging information.

arm/libwvlevel3.a Level3 Library 4445 Sep 11 2017 14:05:15

Test: unit tests on bullhead. Video on Play Movies.  
Kyle ran the GTS tests on loop overnight.

bug: 65379279

Change-Id: I0e0e4b158dbce193abbd8ee2cf6b366060c768b8

libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp

@@ -502,6 +502,9 @@ class WatchDog {
       gave_up_ = true;
       status_ = OEMCrypto_ERROR_INIT_FAILED;
       LOGE("XXX WATCH DOG ERROR XXX");
+      // HACK: this normally just returns an error.  However, we are using it
+      // as a signal to dump debugging information.
+      Level3_GetOEMPublicCertificate(0, nullptr, nullptr);
       SaveFailureInformation();
       // This tells the worker thread to clean up after itself. It is not
       // really needed since we are going to abort.  However, if somebody