1. Figure out the modified libraries from the specifeid kernel file during

runtime/vm/kernel_reader.h

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_KERNEL_READER_H_
 #define RUNTIME_VM_KERNEL_READER_H_
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
 #include <map>
 
@@ skipping 42 matching lines @@
 };
 
 class KernelReader {
  public:
   explicit KernelReader(Program* program);
 
   // Returns the library containing the main procedure, null if there
   // was no main procedure, or a failure object if there was an error.
   dart::Object& ReadProgram();
 
+  // Finds all libraries that have been modified in this incremental
+  // version of the kernel program file.
+  void FindModifiedLibraries(Isolate* isolate,
+                             BitVector* modified_libs,
+                             bool force_reload);
+
   void ReadLibrary(intptr_t kernel_offset);
 
   const dart::String& DartSymbol(StringIndex index) {
     return translation_helper_.DartSymbol(index);
   }
 
   const dart::String& LibraryUri(intptr_t library_index) {
     return translation_helper_.DartSymbol(
         translation_helper_.CanonicalNameString(
             library_canonical_name(library_index)));
@@ skipping 81 matching lines @@
 
   GrowableArray<const dart::Function*> functions_;
   GrowableArray<const dart::Field*> fields_;
 };
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 #endif  // RUNTIME_VM_KERNEL_READER_H_