Fix EstimateMarkingStepSizeTest.

R=wingo@igalia.com
TBR=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/494683002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23237 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap/gc-idle-time-handler.cc

@@ -30,8 +30,9 @@ intptr_t GCIdleTimeHandler::EstimateMarkingStepSize(
     return INT_MAX;
   }
 
-  return static_cast<intptr_t>(marking_step_size *
-                               GCIdleTimeHandler::kConservativeTimeRatio);
+  return Min(static_cast<intptr_t>(marking_step_size *
+                                   GCIdleTimeHandler::kConservativeTimeRatio),
+             static_cast<intptr_t>(INT_MAX));
 }
 }
 }