Break FileIO and URLLoader tests down into individual cases.

ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_file_io.cc

 // Copyright (c) 2011 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 "native_client/src/shared/ppapi_proxy/plugin_ppb_file_io.h"
 
 #include <string.h>
 #include <cmath>
 
 #include "native_client/src/include/nacl_scoped_ptr.h"
@@ skipping 141 matching lines @@
 int32_t Read(PP_Resource file_io,
              int64_t offset,
              char* buffer,
              int32_t bytes_to_read,
              struct PP_CompletionCallback callback) {
   DebugPrintf("PPB_FileIO::Read: file_io=%"NACL_PRIu32", "
               "offset=%"NACL_PRId64", bytes_to_read=%"NACL_PRId32"\n", file_io,
               offset, bytes_to_read);
 
   if (bytes_to_read < 0)
-    bytes_to_read = 0;
-  nacl_abi_size_t buffer_size = bytes_to_read;
+    return PP_ERROR_FAILED;
+  nacl_abi_size_t buffer_size = static_cast<nacl_abi_size_t>(bytes_to_read);
 
   int32_t callback_id =
       CompletionCallbackTable::Get()->AddCallback(callback, buffer);
   if (callback_id == 0)  // Just like Chrome, for now disallow blocking calls.
     return PP_ERROR_BLOCKS_MAIN_THREAD;
 
   int32_t pp_error_or_bytes;
   NaClSrpcError srpc_result =
       PpbFileIORpcClient::PPB_FileIO_Read(
           GetMainSrpcChannel(),
@@ skipping 15 matching lines @@
 int32_t Write(PP_Resource file_io,
               int64_t offset,
               const char* buffer,
               int32_t bytes_to_write,
               struct PP_CompletionCallback callback) {
   DebugPrintf("PPB_FileIO::Write: file_io=%"NACL_PRIu32", offset="
               "%"NACL_PRId64", bytes_to_write=%"NACL_PRId32"\n", file_io,
               offset, bytes_to_write);
 
   if (bytes_to_write < 0)
-    bytes_to_write = 0;
+    return PP_ERROR_FAILED;
   nacl_abi_size_t buffer_size = static_cast<nacl_abi_size_t>(bytes_to_write);
 
   int32_t callback_id =
       CompletionCallbackTable::Get()->AddCallback(callback);
   if (callback_id == 0)  // Just like Chrome, for now disallow blocking calls.
     return PP_ERROR_BLOCKS_MAIN_THREAD;
 
   int32_t pp_error_or_bytes = PP_ERROR_FAILED;
   NaClSrpcError srpc_result = PpbFileIORpcClient::PPB_FileIO_Write(
       GetMainSrpcChannel(),
@@ skipping 84 matching lines @@
     Read,
     Write,
     SetLength,
     Flush,
     Close
   };
   return &file_io_interface;
 }
 
 }  // namespace ppapi_proxy