Remove dependency on Chromium in diagnostic_logging.h.

base/checks.h

Index: base/checks.h
diff --git a/base/checks.h b/base/checks.h
index 1a9a4d18f649a64bb61a62965964c20ea8a0c1df..cff31c05e60d6958d9f40585629e9a17e6f9b62c 100644
--- a/base/checks.h
+++ b/base/checks.h
@@ -14,13 +14,6 @@
 #include <sstream>
 #include <string>
 
-#ifdef WEBRTC_CHROMIUM_BUILD
-// Include logging.h in a Chromium build to enable the overrides mechanism for
-// using Chromium's macros. Otherwise, don't depend on logging.h.
-// TODO(ajm): Ideally, checks.h would be combined with logging.h, but
-// consolidation with system_wrappers/logging.h should happen first.
-#include "webrtc/base/logging.h"
-#endif
 #include "webrtc/typedefs.h"
 
 // The macros here print a message to stderr and abort under various
@@ -59,14 +52,12 @@
 //   RTC_DCHECK.
 //
 // - FATAL() aborts unconditionally.
+//
+// TODO(ajm): Ideally, checks.h would be combined with logging.h, but
+// consolidation with system_wrappers/logging.h should happen first.
 
 namespace rtc {
 
-// The use of overrides/webrtc/base/logging.h in a Chromium build results in
-// redefined macro errors. Fortunately, Chromium's macros can be used as drop-in
-// replacements for the standalone versions.
-//#ifndef WEBRTC_CHROMIUM_BUILD
-
 // Helper macro which avoids evaluating the arguments to a stream if
 // the condition doesn't hold.
 #define RTC_LAZY_STREAM(stream, condition)                                    \
@@ -195,8 +186,6 @@ class FatalMessageVoidify {
   void operator&(std::ostream&) { }
 };
 
-//#endif  // WEBRTC_CHROMIUM_BUILD
-
 #define RTC_UNREACHABLE_CODE_HIT false
 #define RTC_NOTREACHED() RTC_DCHECK(RTC_UNREACHABLE_CODE_HIT)