[Mac] Log stack trace for CHECK in bug 97285.

base/mac/crash_logging.mm

Index: base/mac/crash_logging.mm
diff --git a/base/mac/crash_logging.mm b/base/mac/crash_logging.mm
index ce0db392a8239c9b991a9db35395fb1a81d6dfd2..89f5fba894d6ce7a06d7ffa3541afaca65057cd4 100644
--- a/base/mac/crash_logging.mm
+++ b/base/mac/crash_logging.mm
@@ -6,6 +6,8 @@
 
 #import <Foundation/Foundation.h>
 
+#include "base/logging.h"
+
 namespace base {
 namespace mac {
 
@@ -28,6 +30,30 @@ void ClearCrashKey(NSString* key) {
     g_clear_key_func(key);
 }
 
+void SetCrashKeyFromAddresses(NSString* key,
+                              const void* const* addresses,
+                              size_t count) {
+  NSString* value = @"<null>";
+  if (addresses && count) {
+    const size_t kBreakpadValueMax = 255;
+
+    NSMutableArray* hexBacktrace = [NSMutableArray arrayWithCapacity:count];
+    size_t length = 0;
+    for (size_t i = 0; i < count; ++i) {
+      NSString* s = [NSString stringWithFormat:@"%p", addresses[i]];
+      length += 1 + [s length];
+      if (length > kBreakpadValueMax)
+        break;
+      [hexBacktrace addObject:s];
+    }
+    value = [hexBacktrace componentsJoinedByString:@" "];
+
+    // Warn someone if this exceeds the breakpad limits.
+    DCHECK_LE(strlen([value UTF8String]), kBreakpadValueMax);
+  }
+  base::mac::SetCrashKeyValue(key, value);
+}
+
 ScopedCrashKey::ScopedCrashKey(NSString* key, NSString* value)
     : crash_key_([key retain]) {
   if (g_set_key_func)