Fix bot redness: max_calls can be zero if no call was actually executed.

runtime/vm/flow_graph_inliner.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/flow_graph_inliner.h"
 
 #include "vm/compiler.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 234 matching lines @@
 
     GrowableArray<intptr_t> static_call_counts(num_static_calls);
     for (intptr_t i = 0; i < num_static_calls; ++i) {
       const intptr_t aggregate_count =
           static_calls_[i + static_call_start_ix].
               call->ic_data()->AggregateCount();
       static_call_counts.Add(aggregate_count);
       if (aggregate_count > max_count) max_count = aggregate_count;
     }
 
-
+    // max_count can be 0 if none of the calls was executed.
     for (intptr_t i = 0; i < num_instance_calls; ++i) {
-      ASSERT(max_count > 0);
-      const double ratio =
-          static_cast<double>(instance_call_counts[i]) / max_count;
+      const double ratio = (max_count == 0) ?
+          0.0 : static_cast<double>(instance_call_counts[i]) / max_count;
       instance_calls_[i + instance_call_start_ix].ratio = ratio;
     }
     for (intptr_t i = 0; i < num_static_calls; ++i) {
-      ASSERT(max_count > 0);
-      const double ratio =
-          static_cast<double>(static_call_counts[i]) / max_count;
+      const double ratio = (max_count == 0) ?
+          0.0 : static_cast<double>(static_call_counts[i]) / max_count;
       static_calls_[i + static_call_start_ix].ratio = ratio;
     }
   }
 
   void FindCallSites(FlowGraph* graph) {
     ASSERT(graph != NULL);
 
     const intptr_t instance_call_start_ix = instance_calls_.length();
     const intptr_t static_call_start_ix = static_calls_.length();
     for (BlockIterator block_it = graph->postorder_iterator();
@@ skipping 1092 matching lines @@
         OS::Print("After Inlining of %s\n", flow_graph_->
                   parsed_function().function().ToFullyQualifiedCString());
         FlowGraphPrinter printer(*flow_graph_);
         printer.PrintBlocks();
       }
     }
   }
 }
 
 }  // namespace dart