Adds IDBKeyPath parser / extractor, and provides a mechanism to call it sandboxed.

chrome/browser/utility_process_host.h

Index: chrome/browser/utility_process_host.h
diff --git a/chrome/browser/utility_process_host.h b/chrome/browser/utility_process_host.h
index 8dfee5e1fedac34bf134233f64d98235863ad746..8aadf35cdbf4caf2f161a020cf07e253665b1bc3 100644
--- a/chrome/browser/utility_process_host.h
+++ b/chrome/browser/utility_process_host.h
@@ -18,11 +18,17 @@
 #include "ipc/ipc_channel.h"
 
 class DictionaryValue;
+class IndexedDBKey;
+class SerializedScriptValue;
 class SkBitmap;
 
 // This class acts as the browser-side host to a utility child process.  A
 // utility process is a short-lived sandboxed process that is created to run
 // a specific task.  This class lives solely on the IO thread.
+// If you need a single method call in the sandbox, use StartFooBar(p).
+// If you need multiple batches of work to be done in the sandboxed process,
+// use StartBatchMode(), then multiple calls to StartFooBar(p),
+// then finish with EndBatchMode().
 class UtilityProcessHost : public BrowserChildProcessHost {
  public:
   // An interface to be implemented by consumers of the utility process to
@@ -72,6 +78,18 @@ class UtilityProcessHost : public BrowserChildProcessHost {
     // Called when image data decoding failed.
     virtual void OnDecodeImageFailed() {}
 
+    // Called when we have successfully obtained the IndexedDBKey after
+    // a call to StartIDBKeysFromValuesAndKeyPath.
+    // |id| is the corresponding identifier.
+    // |keys| the corresponding IndexedDBKey.
+    virtual void OnIDBKeysFromValuesAndKeyPathSucceeded(
+        int id, const std::vector<IndexedDBKey>& keys) {}
+
+    // Called when IDBKeyPath has failed.
+    // |id| is the corresponding identifier passed on
+    // StartIDBKeysFromValuesAndKeyPath.
+    virtual void OnIDBKeysFromValuesAndKeyPathFailed(int id) {}
+
    protected:
     friend class base::RefCountedThreadSafe<Client>;
 
@@ -109,12 +127,26 @@ class UtilityProcessHost : public BrowserChildProcessHost {
   // Start image decoding.
   bool StartImageDecoding(const std::vector<unsigned char>& encoded_data);
 
+  // Starts extracting |key_path| from |serialized_values|, and replies with the
+  // corresponding IndexedDBKeys via OnIDBKeysFromValuesAndKeyPathSucceeded.
+  bool StartIDBKeysFromValuesAndKeyPath(
+      int id, const std::vector<SerializedScriptValue>& serialized_values,
+      const string16& key_path);
+
+  // Starts utility process in batch mode. Caller must call EndBatchMode()
+  // to finish the utility process.
+  bool StartBatchMode();
+
+  // Ends the utility process. Must be called after StartBatchMode().
+  void EndBatchMode();
+
  protected:
   // Allow these methods to be overridden for tests.
   virtual FilePath GetUtilityProcessCmd();
 
  private:
-  // Starts a process.  Returns true iff it succeeded.
+  // Starts a process if necessary.  Returns true if it succeeded or a process
+  // has already been started via StartBatchMode().
   bool StartProcess(const FilePath& exposed_dir);
 
   // IPC messages:
@@ -132,6 +164,9 @@ class UtilityProcessHost : public BrowserChildProcessHost {
   // A pointer to our client interface, who will be informed of progress.
   scoped_refptr<Client> client_;
   ChromeThread::ID client_thread_id_;
+  // True when running in batch mode, i.e., StartBatchMode() has been called
+  // and the utility process will run until EndBatchMode().
+  bool is_batch_mode_;
 
   DISALLOW_COPY_AND_ASSIGN(UtilityProcessHost);
 };