Remove print_bootstrap flag as it is not needed anymore considering that we

runtime/vm/bootstrap.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bootstrap.h"
 
 #include "include/dart_api.h"
 
 #include "vm/bootstrap_natives.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
-DEFINE_FLAG(bool, print_bootstrap, false, "Print the bootstrap source.");
-
 #define INIT_LIBRARY(index, name, source, patch)                               \
   { index,                                                                     \
     "dart:"#name, source,                                                      \
     "dart:"#name"-patch", patch }                                              \
 
 typedef struct {
   intptr_t index_;
   const char* uri_;
   const char** source_paths_;
   const char* patch_uri_;
@@ skipping 111 matching lines @@
   }
   ASSERT(utf8_array != NULL);
 
   (*file_close)(stream);
 
   return String::FromUTF8(utf8_array, file_length);
 }
 
 
 static RawError* Compile(const Library& library, const Script& script) {
-  if (FLAG_print_bootstrap) {
-    OS::Print("Bootstrap source '%s':\n%s\n",
-              String::Handle(script.url()).ToCString(),
-              String::Handle(script.Source()).ToCString());
-  }
   bool update_lib_status = (script.kind() == RawScript::kScriptTag ||
                             script.kind() == RawScript::kLibraryTag);
   if (update_lib_status) {
     library.SetLoadInProgress();
   }
   const Error& error = Error::Handle(Compiler::Compile(library, script));
   if (update_lib_status) {
     if (error.IsNull()) {
       library.SetLoaded();
     } else {
@@ skipping 165 matching lines @@
   // Exit the Dart scope.
   Dart_ExitScope();
 
   // Restore the library tag handler for the isolate.
   isolate->set_library_tag_handler(saved_tag_handler);
 
   return error.raw();
 }
 
 }  // namespace dart