[chromedriver] Improve timeout behavior. Prompted by user who executes script on busy page.

chrome/test/chromedriver/util.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/test/chromedriver/util.h"
 
 #include "base/base64.h"
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 99 matching lines @@
 
   void WriteUInt32(uint32 data) {
     WriteBytes(&data, sizeof(data));
   }
 
   void WriteString(const std::string& data) {
     WriteBytes(data.c_str(), data.length());
   }
 
   void WriteBytes(const void* bytes, int size) {
+    if (!size)
+      return;
     size_t next = buffer_.length();
     buffer_.resize(next + size);
     memcpy(&buffer_[next], bytes, size);
   }
 
   const std::string& buffer() const { return buffer_; }
 
  private:
   std::string buffer_;
 };
@@ skipping 13 matching lines @@
     return ReadBytes(data, sizeof(*data));
   }
 
   bool ReadString(std::string* data, int length) {
     if (length < 0)
       return false;
     // Check here to make sure we don't allocate wastefully.
     if (iter_ + length > size_)
       return false;
     data->resize(length);
+    if (length == 0)
+      return true;
     return ReadBytes(&(*data)[0], length);
   }
 
   bool ReadBytes(void* bytes, int size) {
     if (iter_ + size > size_)
       return false;
     memcpy(bytes, &data_[iter_], size);
     iter_ += size;
     return true;
   }
@@ skipping 227 matching lines @@
   if (first_file.empty())
     return Status(kUnknownError, "contained 0 files");
 
   base::FilePath second_file = enumerator.Next();
   if (!second_file.empty())
     return Status(kUnknownError, "contained multiple files");
 
   *file = first_file;
   return Status(kOk);
 }