Fix Process.runSync error handling.

runtime/bin/process_fuchsia.cc

Index: runtime/bin/process_fuchsia.cc
diff --git a/runtime/bin/process_fuchsia.cc b/runtime/bin/process_fuchsia.cc
index 9eb4d747ee9e2b3bbddae3619e70d67004e7cc18..88b115abf8dda9691151e2b559131fae9a8344a8 100644
--- a/runtime/bin/process_fuchsia.cc
+++ b/runtime/bin/process_fuchsia.cc
@@ -441,36 +441,6 @@ static bool ProcessWaitCleanup(intptr_t out,
 }
 
 
-class BufferList : public BufferListBase {
- public:
-  BufferList() {}
-
-  bool Read(int fd, intptr_t available) {
-    // Read all available bytes.
-    while (available > 0) {
-      if (free_size_ == 0) {
-        Allocate();
-      }
-      ASSERT(free_size_ > 0);
-      ASSERT(free_size_ <= kBufferSize);
-      intptr_t block_size = dart::Utils::Minimum(free_size_, available);
-      intptr_t bytes = NO_RETRY_EXPECTED(
-          read(fd, reinterpret_cast<void*>(FreeSpaceAddress()), block_size));
-      if (bytes < 0) {
-        return false;
-      }
-      data_size_ += bytes;
-      free_size_ -= bytes;
-      available -= bytes;
-    }
-    return true;
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(BufferList);
-};
-
-
 bool Process::Wait(intptr_t pid,
                    intptr_t in,
                    intptr_t out,
@@ -570,6 +540,8 @@ bool Process::Wait(intptr_t pid,
   // All handles closed and all data read.
   result->set_stdout_data(out_data.GetData());
   result->set_stderr_data(err_data.GetData());
+  DEBUG_ASSERT(out_data.IsEmpty());
+  DEBUG_ASSERT(err_data.IsEmpty());
 
   // Calculate the exit code.
   intptr_t exit_code = exit_code_data.ints[0];