Attach snapshot data blob to the isolate.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index fa32ba3cdfb3cf77c803da527e480832230c591b..c2dd50517c6f743798da4e75dca22a089b2836c1 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -92,6 +92,7 @@ class Promise;
 class RawOperationDescriptor;
 class Script;
 class Signature;
+class StartupData;
 class StackFrame;
 class StackTrace;
 class String;
@@ -4646,7 +4647,8 @@ class V8_EXPORT Isolate {
     CreateParams()
         : entry_hook(NULL),
           code_event_handler(NULL),
-          enable_serializer(false) {}
+          enable_serializer(false),
+          snapshot_blob(NULL) {}
 
     /**
      * The optional entry_hook allows the host application to provide the
@@ -4672,6 +4674,11 @@ class V8_EXPORT Isolate {
      * This flag currently renders the Isolate unusable.
      */
     bool enable_serializer;
+
+    /**
+     * Explicitly specify a startup snapshot blob. The embedder owns the blob.
+     */
+    StartupData* snapshot_blob;
   };
 
 
@@ -5397,7 +5404,7 @@ class V8_EXPORT V8 {
    * Returns { NULL, 0 } on failure.
    * The caller owns the data array in the return value.
    */
-  static StartupData CreateSnapshotDataBlob(char* custom_source = NULL);
+  static StartupData CreateSnapshotDataBlob(const char* custom_source = NULL);
 
   /**
    * Adds a message listener.