[crankshaft] Remove graph builder from optimized compile job.

There is no reason to keep around the HOptimizedGraphBuilder after the
graph has successfully been built. Later phases in OptimizedCompileJob
should not rely on it anymore.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1756183002

Cr-Commit-Position: refs/heads/master@{#34440}

src/compiler.cc

@@ -490,13 +490,13 @@ OptimizedCompileJob::Status OptimizedCompileJob::CreateGraph() {
         info()->shared_info()->disable_optimization_reason());
   }
 
-  graph_builder_ = (info()->is_tracking_positions() || FLAG_trace_ic)
-                       ? new (info()->zone())
-                             HOptimizedGraphBuilderWithPositions(info())
-                       : new (info()->zone()) HOptimizedGraphBuilder(info());
+  HOptimizedGraphBuilder* graph_builder =
+      (info()->is_tracking_positions() || FLAG_trace_ic)
+          ? new (info()->zone()) HOptimizedGraphBuilderWithPositions(info())
+          : new (info()->zone()) HOptimizedGraphBuilder(info());
 
   Timer t(this, &time_taken_to_create_graph_);
-  graph_ = graph_builder_->CreateGraph();
+  graph_ = graph_builder->CreateGraph();
 
   if (isolate()->has_pending_exception()) {
     return SetLastStatus(FAILED);
@@ -533,7 +533,7 @@ OptimizedCompileJob::Status OptimizedCompileJob::OptimizeGraph() {
     chunk_ = LChunk::NewChunk(graph_);
     if (chunk_ != NULL) return SetLastStatus(SUCCEEDED);
   } else if (bailout_reason != kNoReason) {
-    graph_builder_->Bailout(bailout_reason);
+    info_->AbortOptimization(bailout_reason);
   }
 
   return SetLastStatus(BAILED_OUT);

src/compiler.h

@@ -509,7 +509,6 @@ class CompilationHandleScope BASE_EMBEDDED {
 
 
 class HGraph;
-class HOptimizedGraphBuilder;
 class LChunk;
 
 // A helper class that calls the three compilation phases in
@@ -522,7 +521,6 @@ class OptimizedCompileJob: public ZoneObject {
  public:
   explicit OptimizedCompileJob(CompilationInfo* info)
       : info_(info),
-        graph_builder_(NULL),
         graph_(NULL),
         chunk_(NULL),
         last_status_(FAILED),
@@ -559,7 +557,6 @@ class OptimizedCompileJob: public ZoneObject {
 
  private:
   CompilationInfo* info_;
-  HOptimizedGraphBuilder* graph_builder_;
   HGraph* graph_;
   LChunk* chunk_;
   base::TimeDelta time_taken_to_create_graph_;