Implement Dump-on-DCHECK (via a new LogSeverity).

base/logging_unittest.cc

Index: base/logging_unittest.cc
diff --git a/base/logging_unittest.cc b/base/logging_unittest.cc
index f41cce2f43b390fa9603a14f3f689fe87d0dcb33..1814065567104e2374b5f1620ba298c14f8349cd 100644
--- a/base/logging_unittest.cc
+++ b/base/logging_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/compiler_specific.h"
+#include "base/debug/dump_without_crashing.h"
 #include "base/logging.h"
 #include "base/macros.h"
 
@@ -191,7 +192,7 @@ TEST_F(LoggingTest, CheckStreamsAreLazy) {
 #endif
 
 TEST_F(LoggingTest, DebugLoggingReleaseBehavior) {
-#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+#if DCHECK_IS_ON()
   int debug_only_variable = 1;
 #endif
   // These should avoid emitting references to |debug_only_variable|
@@ -326,6 +327,29 @@ TEST_F(LoggingTest, CheckEqStatements) {
     CHECK_EQ(false, true);           // Unreached.
 }
 
+namespace {
+
+int fake_dump_without_crashing_count = 0;
+void FakeDumpWithoutCrashing() {
+  fake_dump_without_crashing_count++;
+}
+
+} // namespace
+
+TEST_F(LoggingTest, LogMessageDump) {
+  // Replace the dump-without-crashing function, to test.
+  base::debug::SetDumpWithoutCrashingFunction(&FakeDumpWithoutCrashing);
+
+  // LOG_DUMP is an internal severity level for use by dump-on-DCHECK, so
+  // we must call LogMessage() directly, rather than using LOG(DUMP).
+  LogMessage(__FILE__, __LINE__, LOG_DUMP, new std::string);
+  EXPECT_EQ(1, fake_dump_without_crashing_count);
+  LogMessage(__FILE__, __LINE__, LOG_DUMP, new std::string);
+  EXPECT_EQ(1, fake_dump_without_crashing_count);
+
+  base::debug::SetDumpWithoutCrashingFunction(nullptr);
+}
+
 // Test that defining an operator<< for a type in a namespace doesn't prevent
 // other code in that namespace from calling the operator<<(ostream, wstring)
 // defined by logging.h. This can fail if operator<<(ostream, wstring) can't be