Compress sources of JS libraries in addition to the snapshot.

src/bootstrapper.h

Index: src/bootstrapper.h
diff --git a/src/bootstrapper.h b/src/bootstrapper.h
index 2e05452a8c9e8b6e4710a4b0dcac0ed720dcba06..abf61b9fe581f523ad60198a9e312e73f947a118 100644
--- a/src/bootstrapper.h
+++ b/src/bootstrapper.h
@@ -168,8 +168,9 @@ class BootstrapperActive BASE_EMBEDDED {
 class NativesExternalStringResource
     : public v8::String::ExternalAsciiStringResource {
  public:
-  explicit NativesExternalStringResource(Bootstrapper* bootstrapper,
-                                         const char* source);
+  NativesExternalStringResource(Bootstrapper* bootstrapper,
+                                const char* source,
+                                size_t length);
 
   const char* data() const {
     return data_;