Add Clang static analyzer to Clang toolchain defs in GN

base/logging.h

Index: base/logging.h
diff --git a/base/logging.h b/base/logging.h
index 7854e3934e974b4670930d6855f3ab8699a8376f..07e2a02e2d256a7027f6cf84614cea323eae2f5f 100644
--- a/base/logging.h
+++ b/base/logging.h
@@ -726,7 +726,27 @@ const LogSeverity LOG_DCHECK = LOG_INFO;
   LAZY_STREAM(PLOG_STREAM(DCHECK), false)                               \
   << "Check failed: " #condition ". "
 
-#else  // _PREFAST_
+#elif defined(__clang_analyzer__)
+
+// Keeps the static analyzer from proceeding along the current codepath,
+// otherwise false positive errors may be generated  by null pointer checks.
+inline constexpr bool AnalyzerNoReturn() __attribute__((analyzer_noreturn)) {
+  return false;
+}
+
+#define DCHECK(condition)                                                   \
+  LAZY_STREAM(                                                              \
+      LOG_STREAM(DCHECK),                                                   \
+      DCHECK_IS_ON() ? (logging::AnalyzerNoReturn(), !(condition)) : false) \
+      << "Check failed: " #condition ". "
+
+#define DPCHECK(condition)                                                  \
+  LAZY_STREAM(                                                              \
+      PLOG_STREAM(DCHECK),                                                  \
+      DCHECK_IS_ON() ? (logging::AnalyzerNoReturn(), !(condition)) : false) \
+      << "Check failed: " #condition ". "
+
+#else
 
 #define DCHECK(condition)                                                \
   LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON() ? !(condition) : false) \
@@ -736,7 +756,7 @@ const LogSeverity LOG_DCHECK = LOG_INFO;
   LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON() ? !(condition) : false) \
       << "Check failed: " #condition ". "
 
-#endif  // _PREFAST_
+#endif
 
 // Helper macro for binary operators.
 // Don't use this macro directly in your code, use DCHECK_EQ et al below.