Add dvlog_always_on to enable DVLOG without DEBUG and DCHECK option

ppapi/cpp/logging.h

Index: ppapi/cpp/logging.h
diff --git a/ppapi/cpp/logging.h b/ppapi/cpp/logging.h
index d0a4f5b29a5635973571a9638900251379c56a41..098cb652a77a6b33d0043aed6463ed1f24dc990f 100644
--- a/ppapi/cpp/logging.h
+++ b/ppapi/cpp/logging.h
@@ -13,7 +13,11 @@
 /// This macro asserts that 'a' evaluates to true. In debug mode, this macro
 /// will crash the program if the assertion evaluates to false. It (typically)
 /// has no effect in release mode.
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
 #define PP_DCHECK(a) assert(a)
+#else  // !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+#define PP_DCHECK(a)
+#endif  // !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
 
 /// This macro asserts false in debug builds. It's used in code paths that you
 /// don't expect to execute.
@@ -29,6 +33,10 @@
 /// // Do stuff to the pointer, since you know it's valid.
 /// pointer->DoSomething();
 /// @endcode
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
 #define PP_NOTREACHED() assert(false)
+#else  // !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+#define PP_NOTREACHED()
+#endif  // !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
 
 #endif  // PPAPI_CPP_LOGGING_H_