Replace all use of the VERIFY macro.

Replaced by assigning value to a local variable, followed by a DCHECK.
Also deletes dead test code under the always false TEST_DIGEST define.

BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2623473004
Cr-Commit-Position: refs/heads/master@{#16476}

webrtc/base/openssladapter.cc

@@ -27,6 +27,7 @@
 
 #include "webrtc/base/arraysize.h"
 #include "webrtc/base/checks.h"
+#include "webrtc/base/common.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/openssl.h"
 #include "webrtc/base/safe_conversions.h"