Fixes some memory leaks in //runtime/bin

runtime/bin/process_linux.cc

Index: runtime/bin/process_linux.cc
diff --git a/runtime/bin/process_linux.cc b/runtime/bin/process_linux.cc
index 30f188f1299209ae7bac3ca51af82ae68bdcb028..572ced76e1b25188d4e86d1d6c4caf57b2c76d7f 100644
--- a/runtime/bin/process_linux.cc
+++ b/runtime/bin/process_linux.cc
@@ -16,6 +16,7 @@
 #include <sys/wait.h>  // NOLINT
 #include <unistd.h>  // NOLINT
 
+#include "bin/dartutils.h"
 #include "bin/fdutils.h"
 #include "bin/lockers.h"
 #include "bin/log.h"
@@ -634,7 +635,9 @@ class ProcessStarter {
     int actual_errno = errno;
     // If CleanupAndReturnError is called without an actual errno make
     // sure to return an error anyway.
-    if (actual_errno == 0) actual_errno = EPERM;
+    if (actual_errno == 0) {
+      actual_errno = EPERM;
+    }
     SetChildOsErrorMessage();
     CloseAllPipes();
     return actual_errno;
@@ -643,8 +646,9 @@ class ProcessStarter {
 
   void SetChildOsErrorMessage() {
     const int kBufferSize = 1024;
-    char error_buf[kBufferSize];
-    *os_error_message_ = strdup(Utils::StrError(errno, error_buf, kBufferSize));
+    char* error_message = DartUtils::ScopedCString(kBufferSize);
+    Utils::StrError(errno, error_message, kBufferSize);
+    *os_error_message_ = error_message;
   }
 
 
@@ -679,7 +683,7 @@ class ProcessStarter {
 
   void ReadChildError() {
     const int kMaxMessageSize = 256;
-    char* message = static_cast<char*>(malloc(kMaxMessageSize));
+    char* message = DartUtils::ScopedCString(kMaxMessageSize);
     if (message != NULL) {
       FDUtils::ReadFromBlocking(exec_control_[0], message, kMaxMessageSize);
       message[kMaxMessageSize - 1] = '\0';