Refactor Mac crash key reporting - move to base/mac/crash_logging.{h,mm}

chrome/app/breakpad_mac_stubs.mm

Index: chrome/app/breakpad_mac_stubs.mm
diff --git a/chrome/app/breakpad_mac_stubs.mm b/chrome/app/breakpad_mac_stubs.mm
index b07ded6fbb8dc83da59932b873ae4fd990d37e98..33587dc3e795f0cec8668132d7428c92895f2606 100644
--- a/chrome/app/breakpad_mac_stubs.mm
+++ b/chrome/app/breakpad_mac_stubs.mm
@@ -21,22 +21,3 @@ void DestructCrashReporter() {
 
 void InitCrashReporter() {
 }
-
-void SetCrashKeyValue(NSString* key, NSString* value) {
-}
-
-void ClearCrashKeyValue(NSString* key) {
-}
-
-// NOTE(shess): These functions could clearly be replaced by stubs,
-// but since they are seldom-used helpers, it seemed more reasonable
-// to duplicate them from the primary implementation in
-// breakpad_mac.mm.
-ScopedCrashKey::ScopedCrashKey(NSString* key, NSString* value)
-    : crash_key_([key retain]) {
-  SetCrashKeyValue(crash_key_.get(), value);
-}
-
-ScopedCrashKey::~ScopedCrashKey() {
-  ClearCrashKeyValue(crash_key_.get());
-}