[Sheriff] Revert "Let SetEntropySource() fail if called after V8::Initialize()."

This reverts commit 16889 for breaking the webkit tests.

TBR=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/23530071

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16896 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -4540,9 +4540,6 @@ class V8_EXPORT V8 {
   /**
    * Allows the host application to provide a callback which can be used
    * as a source of entropy for random number generators.
-   *
-   * \note Setting an entropy source can only be done very early prior to
-   *   calling Initialize().
    */
   static void SetEntropySource(EntropySource source);
 

src/api.cc

@@ -4942,13 +4942,6 @@ bool v8::V8::Initialize() {
 
 
 void v8::V8::SetEntropySource(EntropySource entropy_source) {
-  // The entropy source must be set before the library is initialized,
-  // as otherwise not all random number generators will pick up the
-  // entropy source and will fall back to weak entropy instead.
-  i::Isolate* isolate = i::Isolate::UncheckedCurrent();
-  ApiCheck(isolate != NULL && isolate->IsInitialized(),
-           "v8::V8::SetEntropySource",
-           "Cannot set entropy source once V8 is initialized.");
   i::RandomNumberGenerator::SetEntropySource(entropy_source);
 }