Add --hot-reload-test-mode flag to embedder and wire it up to test.py

runtime/vm/code_generator.cc

 // Copyright (c) 2013, 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/code_generator.h"
 
 #include "vm/assembler.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 45 matching lines @@
 
 DEFINE_FLAG(int, stacktrace_every, 0,
             "Compute debugger stacktrace on every N stack overflow checks");
 DEFINE_FLAG(charp, stacktrace_filter, NULL,
             "Compute stacktrace in named function on stack overflow checks");
 DEFINE_FLAG(charp, deoptimize_filter, NULL,
             "Deoptimize in named function on stack overflow checks");
 
 DECLARE_FLAG(int, reload_every);
 DECLARE_FLAG(bool, reload_every_optimized);
+DECLARE_FLAG(bool, reload_every_back_off);
 
 #ifdef DEBUG
 DEFINE_FLAG(charp, gc_at_instance_allocation, NULL,
             "Perform a GC before allocation of instances of "
             "the specified class");
 #endif
 
 DEFINE_RUNTIME_ENTRY(TraceFunctionEntry, 1) {
   const Function& function = Function::CheckedHandle(arguments.ArgAt(0));
   const String& function_name = String::Handle(function.name());
@@ skipping 1213 matching lines @@
       OS::PrintErr("*** Computing stacktrace (%s)\n",
                    function.ToFullyQualifiedCString());
       do_stacktrace = true;
     }
   }
   if (do_deopt) {
     // TODO(turnidge): Consider using DeoptimizeAt instead.
     DeoptimizeFunctionsOnStack();
   }
   if (do_reload) {
+    if (FLAG_reload_every_back_off) {
+      FLAG_reload_every *= 2;
+    }
     NOT_IN_PRODUCT(isolate->ReloadSources();)
   }
   if (FLAG_support_debugger && do_stacktrace) {
     String& var_name = String::Handle();
     Instance& var_value = Instance::Handle();
     // Collecting the stack trace and accessing local variables
     // of frames may trigger parsing of functions to compute
     // variable descriptors of functions. Parsing may trigger
     // code execution, e.g. to compute compile-time constants. Thus,
     // disable FLAG_stacktrace_every during trace collection to prevent
@@ skipping 569 matching lines @@
   const intptr_t elm_size = old_data.ElementSizeInBytes();
   const TypedData& new_data =
       TypedData::Handle(TypedData::New(cid, new_size, Heap::kOld));
   TypedData::Copy(new_data, 0, old_data, 0, old_size * elm_size);
   typed_data_cell.SetAt(0, new_data);
   arguments.SetReturn(new_data);
 }
 
 
 }  // namespace dart