Add usage and collision details to the hash table data structure in order to determine effectivenes…

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/block_scheduler.h"
@@ skipping 1568 matching lines @@
   }
   UNREACHABLE();
   return Object::null();
 }
 
 
 void Compiler::AbortBackgroundCompilation(intptr_t deopt_id, const char* msg) {
   if (FLAG_trace_compiler) {
     THR_Print("ABORT background compilation: %s\n", msg);
   }
+NOT_IN_PRODUCT(
   TimelineStream* stream = Timeline::GetCompilerStream();
   ASSERT(stream != NULL);
   TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
     event->Instant("AbortBackgroundCompilation");
     event->SetNumArguments(1);
     event->CopyArgument(0, "reason", msg);
     event->Complete();
   }
+)  // !PRODUCT
   ASSERT(Compiler::IsBackgroundCompilation());
   Thread::Current()->long_jump_base()->Jump(
       deopt_id, Object::background_compilation_error());
 }
 
 
 // C-heap allocated background compilation queue element.
 class QueueElement {
  public:
   explicit QueueElement(const Function& function)
@@ skipping 391 matching lines @@
 }
 
 
 void BackgroundCompiler::EnsureInit(Thread* thread) {
   UNREACHABLE();
 }
 
 #endif  // DART_PRECOMPILED_RUNTIME
 
 }  // namespace dart