Added new ReadFileToString API with a max_size argument

base/files/file_util_proxy_unittest.cc

Index: base/files/file_util_proxy_unittest.cc
diff --git a/base/files/file_util_proxy_unittest.cc b/base/files/file_util_proxy_unittest.cc
index 30c77d39884c3ce82004bc78e6a9871f62f08936..971d62417d022d5cbd30c20be948260a1a7532e4 100644
--- a/base/files/file_util_proxy_unittest.cc
+++ b/base/files/file_util_proxy_unittest.cc
@@ -221,6 +221,43 @@ TEST_F(FileUtilProxyTest, CreateTemporary) {
   EXPECT_TRUE(base::DeleteFile(path_, false));
 }
 
+TEST_F(FileUtilProxyTest, ReadFileToString) {

[Andrew T Wilson (Slow), 2014/02/11 10:27:12]

I think this code should live in base/file_util_unittest.cc, not in
file_util_proxy_unittest.cc.

[kaliamoorthi, 2014/02/11 16:29:16]

Done.

+  const char kTestData[] = "0123";
+  std::string data;
+
+  ASSERT_EQ(4, file_util::WriteFile(test_path(), kTestData, 4));
+
+  EXPECT_TRUE(ReadFileToString(test_path(), &data));
+  EXPECT_EQ(kTestData, data);
+
+  data.clear();
+  EXPECT_FALSE(ReadFileToString(test_path(), &data, 0));
+  EXPECT_EQ(data.length(), (size_t)0);
+
+  data.clear();
+  EXPECT_FALSE(ReadFileToString(test_path(), &data, 2));
+  EXPECT_EQ(data.length(), (size_t)0);
+
+  data.clear();
+  EXPECT_FALSE(ReadFileToString(test_path(), &data, 3));
+  EXPECT_EQ(data.length(), (size_t)0);
+
+  data.clear();
+  EXPECT_TRUE(ReadFileToString(test_path(), &data, 4));
+  EXPECT_EQ("0123", data);
+
+  data.clear();
+  EXPECT_TRUE(ReadFileToString(test_path(), &data, 6));
+  EXPECT_EQ("0123", data);
+
+  EXPECT_TRUE(ReadFileToString(test_path(), NULL, 6));
+
+  EXPECT_TRUE(ReadFileToString(test_path(), NULL));
+
+  // Make sure we can & do delete the created file to prevent leaks on the bots.
+  EXPECT_TRUE(base::DeleteFile(test_path(), false));

[Andrew T Wilson (Slow), 2014/02/11 10:27:12]

Add another call to make sure trying to read a deleted file fails:

EXPECT_FALSE(ReadFileToString(test_path(), NULL));

+}
+
 TEST_F(FileUtilProxyTest, GetFileInfo_File) {
   // Setup.
   ASSERT_EQ(4, file_util::WriteFile(test_path(), "test", 4));