Error checking for Stdio calls

runtime/bin/stdio_fuchsia.cc

Index: runtime/bin/stdio_fuchsia.cc
diff --git a/runtime/bin/stdio_fuchsia.cc b/runtime/bin/stdio_fuchsia.cc
index e29749988373aedb3ade708c299a454a3da2e1ab..8b77fbce46ae97df2dabcb9c589adff2b304f3b9 100644
--- a/runtime/bin/stdio_fuchsia.cc
+++ b/runtime/bin/stdio_fuchsia.cc
@@ -12,31 +12,33 @@
 namespace dart {
 namespace bin {
 
-int Stdin::ReadByte() {
+bool Stdin::ReadByte(int* byte) {
   UNIMPLEMENTED();
-  return -1;
+  return false;
 }
 
 
-bool Stdin::GetEchoMode() {
+bool Stdin::GetEchoMode(bool* enabled) {
   UNIMPLEMENTED();
   return false;
 }
 
 
-void Stdin::SetEchoMode(bool enabled) {
+bool Stdin::SetEchoMode(bool enabled) {
   UNIMPLEMENTED();
+  return false;
 }
 
 
-bool Stdin::GetLineMode() {
+bool Stdin::GetLineMode(bool* enabled) {
   UNIMPLEMENTED();
   return false;
 }
 
 
-void Stdin::SetLineMode(bool enabled) {
+bool Stdin::SetLineMode(bool enabled) {
   UNIMPLEMENTED();
+  return false;
 }