Remove support for generating visualizer format file for the flowgraph.

runtime/vm/compiler.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/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
@@ skipping 147 matching lines @@
       flow_graph = builder.BuildGraph(FlowGraphBuilder::kNotInlining);
 
       // Transform to SSA.
       if (optimized) flow_graph->ComputeSSA(0);  // Start at virtual register 0.
 
       if (FLAG_print_flow_graph) {
         OS::Print("Before Optimizations\n");
         FlowGraphPrinter printer(*flow_graph);
         printer.PrintBlocks();
       }
-      if (Dart::flow_graph_writer() != NULL) {
-        // Write flow graph to file.
-        FlowGraphVisualizer printer(*flow_graph);
-        printer.PrintFunction();
-      }
 
       if (optimized) {
         flow_graph->ComputeUseLists();
 
         FlowGraphOptimizer optimizer(flow_graph);
         optimizer.ApplyICData();
 
         // Compute the use lists.
         flow_graph->ComputeUseLists();
 
@@ skipping 413 matching lines @@
     result = isolate->object_store()->sticky_error();
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart