Implement Dump-on-DCHECK (via alternate DCHECK and DCHECK_OP macro implementations).

base/logging.cc

Index: base/logging.cc
diff --git a/base/logging.cc b/base/logging.cc
index 4904f18646f122872cbd02eaff96e58576d32710..f0e077c5784f0802eec8f0af8ba4120cae2f3399 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -57,6 +57,7 @@ typedef pthread_mutex_t* MutexHandle;
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/debug/debugger.h"
+#include "base/debug/dump_without_crashing.h"
 #include "base/debug/stack_trace.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/string_piece.h"
@@ -124,6 +125,7 @@ bool show_error_dialogs = false;
 // An assert handler override specified by the client to be called instead of
 // the debug message dialog and process termination.
 LogAssertHandlerFunction log_assert_handler = nullptr;
+
 // A log message handler that gets notified of every log message we process.
 LogMessageHandlerFunction log_message_handler = nullptr;
 
@@ -343,6 +345,20 @@ void CloseLogFileUnlocked() {
 
 }  // namespace
 
+#if defined(DCHECK_IS_DUMP_WITHOUT_CRASH)
+// Used to implement dump-on-DCHECK. See crbug.com/596231.
+void DCheckDumpWithoutCrashingOnce() {
+  // To ensure we don't risk spamming Crash with dump-on-DCHECK reports we
+  // log only the first[*] DCHECK to fail once DumpWithoutCrashing() is
+  // working.
+  // [*] This is racey, but in the pathological case still only results in
+  // one dump per-racing-thread, rather than one per-process.
+  static bool dump_on_dcheck = true;
+  if (dump_on_dcheck)
+    dump_on_dcheck = !base::debug::DumpWithoutCrashing();
+}
+#endif  // defined(DCHECK_IS_DUMP_WITHOUT_CRASH)
+
 // This is never instantiated, it's just used for EAT_STREAM_PARAMETERS to have
 // an object of the correct type on the LHS of the unused part of the ternary
 // operator.