Unflake and speedup JsNative*Sample cpu profile tests

src/profile-generator.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/profile-generator-inl.h"
 
 #include "src/compiler.h"
 #include "src/debug.h"
@@ skipping 451 matching lines @@
 
 bool CpuProfilesCollection::StartProfiling(const char* title,
                                            bool record_samples) {
   current_profiles_semaphore_.Wait();
   if (current_profiles_.length() >= kMaxSimultaneousProfiles) {
     current_profiles_semaphore_.Signal();
     return false;
   }
   for (int i = 0; i < current_profiles_.length(); ++i) {
     if (strcmp(current_profiles_[i]->title(), title) == 0) {
-      // Ignore attempts to start profile with the same title.
+      // Ignore attempts to start profile with the same title...
       current_profiles_semaphore_.Signal();
-      return false;
+      // ... though return true to force it collect a sample.
+      return true;
     }
   }
   current_profiles_.Add(new CpuProfile(title, record_samples));
   current_profiles_semaphore_.Signal();
   return true;
 }
 
 
 CpuProfile* CpuProfilesCollection::StopProfiling(const char* title) {
   const int title_len = StrLength(title);
@@ skipping 181 matching lines @@
     case OTHER:
     case EXTERNAL:
       return program_entry_;
     case IDLE:
       return idle_entry_;
     default: return NULL;
   }
 }
 
 } }  // namespace v8::internal