Use a random seed for the string hash algorithm.

src/profile-generator.cc

Index: src/profile-generator.cc
===================================================================
--- src/profile-generator.cc	(revision 10321)
+++ src/profile-generator.cc	(working copy)
@@ -110,7 +110,7 @@
   Vector<char> dst = Vector<char>::New(len + 1);
   OS::StrNCpy(dst, src, len);
   dst[len] = '\0';
-  uint32_t hash = HashSequentialString(dst.start(), len);
+  uint32_t hash = HashSequentialString(dst.start(), len, ISOLATE->HasherSeed());
   return AddOrDisposeString(dst.start(), hash);
 }
 
@@ -143,7 +143,7 @@
     DeleteArray(str.start());
     return format;
   }
-  uint32_t hash = HashSequentialString(str.start(), len);
+  uint32_t hash = HashSequentialString(str.start(), len, ISOLATE->HasherSeed());
   return AddOrDisposeString(str.start(), hash);
 }
 
@@ -153,7 +153,8 @@
     int length = Min(kMaxNameSize, name->length());
     SmartArrayPointer<char> data =
         name->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL, 0, length);
-    uint32_t hash = HashSequentialString(*data, length);
+    uint32_t hash =
+        HashSequentialString(*data, length, name->GetIsolate()->HasherSeed());
     return AddOrDisposeString(data.Detach(), hash);
   }
   return "";
@@ -1501,7 +1502,9 @@
 uint64_t HeapObjectsMap::GenerateId(v8::RetainedObjectInfo* info) {
   uint64_t id = static_cast<uint64_t>(info->GetHash());
   const char* label = info->GetLabel();
-  id ^= HashSequentialString(label, static_cast<int>(strlen(label)));
+  id ^= HashSequentialString(label,
+                             static_cast<int>(strlen(label)),
+                             ISOLATE->HasherSeed());
   intptr_t element_count = info->GetElementCount();
   if (element_count != -1)
     id ^= ComputeIntegerHash(static_cast<uint32_t>(element_count));