Added new ReadFileToString API with a max_size argument

base/files/file_util_proxy_unittest.cc

 // Copyright (c) 2012 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 "base/files/file_util_proxy.h"
 
 #include <map>
 
 #include "base/bind.h"
 #include "base/file_util.h"
@@ skipping 199 matching lines @@
   EXPECT_EQ(4, WritePlatformFile(file_, 0, "test", 4));
 #endif
   EXPECT_TRUE(ClosePlatformFile(file_));
   file_ = kInvalidPlatformFileValue;
 
   // Make sure the written data can be read from the returned path.
   std::string data;
   EXPECT_TRUE(ReadFileToString(path_, &data));
   EXPECT_EQ("test", data);
 
+  EXPECT_FALSE(ReadFileToString(path_, &data, 0));

[Andrew T Wilson (Slow), 2014/02/10 14:29:46]

Can we move these to a separate test?

Also, can you add a test for ReadFileToString(path, NULL) which should return
true if there were no errors (since this functionality was broken in your CL)?

[kaliamoorthi, 2014/02/11 10:10:45]

Done.

+  EXPECT_FALSE(ReadFileToString(path_, &data, 2));

[bartfab (slow), 2014/02/10 14:55:37]

Nit: Could you order these tests by increasing maxsize? They appear a bit
chaotic right now.

[kaliamoorthi, 2014/02/11 10:10:45]

Done.

+  EXPECT_TRUE(ReadFileToString(path_, &data, 6));
+  EXPECT_FALSE(ReadFileToString(path_, &data, 3));
+  EXPECT_TRUE(ReadFileToString(path_, &data, 4));
+
   // Make sure we can & do delete the created file to prevent leaks on the bots.
   EXPECT_TRUE(base::DeleteFile(path_, false));
 }
 
 TEST_F(FileUtilProxyTest, GetFileInfo_File) {
   // Setup.
   ASSERT_EQ(4, file_util::WriteFile(test_path(), "test", 4));
   File::Info expected_info;
   GetFileInfo(test_path(), &expected_info);
 
@@ skipping 171 matching lines @@
   char buffer[53];
   EXPECT_EQ(53, base::ReadFile(test_path(), buffer, 53));
   int i = 0;
   for (; i < 10; ++i)
     EXPECT_EQ(kTestData[i], buffer[i]);
   for (; i < 53; ++i)
     EXPECT_EQ(0, buffer[i]);
 }
 
 }  // namespace base