Improve the casing of Stackmap and Stacktrace.

runtime/lib/stacktrace.h

Index: runtime/lib/stacktrace.h
diff --git a/runtime/lib/stacktrace.h b/runtime/lib/stacktrace.h
index e6bccae510603532ba291ed443089384bcf197ae..fe67a9dcd9723ee19b778aba3b86dc901e35a0b0 100644
--- a/runtime/lib/stacktrace.h
+++ b/runtime/lib/stacktrace.h
@@ -7,14 +7,14 @@
 
 namespace dart {
 
-class Stacktrace;
+class StackTrace;
 
-// Creates a Stacktrace object from the current stack.  Skips the
+// Creates a StackTrace object from the current stack.  Skips the
 // first skip_frames Dart frames.
 //
 // This function is exposed to provide stack trace printing in
 // assertion failures, etc.
-const Stacktrace& GetCurrentStacktrace(int skip_frames);
+const StackTrace& GetCurrentStackTrace(int skip_frames);
 
 }  // namespace dart