Revert "Updating the mapped_file_avoid_mmap_posix implementation."

net/disk_cache/mapped_file_unittest.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 "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/strings/string_util.h"
 #include "net/disk_cache/disk_cache_test_base.h"
 #include "net/disk_cache/disk_cache_test_util.h"
 #include "net/disk_cache/mapped_file.h"
@@ skipping 71 matching lines @@
               &completed));
   if (!completed)
     expected++;
 
   helper.WaitUntilCacheIoFinished(expected);
 
   EXPECT_EQ(expected, helper.callbacks_called());
   EXPECT_FALSE(helper.callback_reused_error());
   EXPECT_STREQ(buffer1, buffer2);
 }
-
-TEST_F(DiskCacheTest, MappedFile_MemoryAccess) {
-  const size_t page_size = 4096;
-  const size_t buffer_size = 20;
-  size_t file_sizes[] = { 2 * page_size,
-                          8 * page_size + buffer_size};
-  bool full_writes[] = { false, true };
-  for (size_t i = 0; i < arraysize(file_sizes); ++i) {
-    size_t file_size = file_sizes[i];
-    for (size_t j = 0; j < arraysize(full_writes); ++j) {
-      bool full_write = full_writes[j];
-      base::FilePath filename = cache_path_.AppendASCII("a_test");
-      scoped_refptr<disk_cache::MappedFile> file(new disk_cache::MappedFile);
-      ASSERT_TRUE(CreateCacheTestFileWithSize(filename, file_size));
-      ASSERT_TRUE(file->Init(filename, file_size));
-
-      char buffer1[buffer_size];
-      char buffer2[buffer_size];
-      CacheTestFillBuffer(buffer1, buffer_size, false);
-
-      char* buffer = reinterpret_cast<char*>(file->buffer());
-
-      memcpy(buffer, buffer1, buffer_size);
-      if (full_write) {
-        for (size_t k = page_size; k <= file_size / 2; k += page_size) {
-          memcpy(buffer + k, buffer1, buffer_size);
-        }
-      }
-
-      file->Flush();
-
-      file->Read(buffer2, buffer_size, 0);
-      EXPECT_EQ(0, strncmp(buffer1, buffer2, buffer_size));
-      if (full_write) {
-        for (size_t k = page_size; k <= file_size / 2; k += page_size) {
-          file->Read(buffer2, buffer_size, k);
-          EXPECT_EQ(0, strncmp(buffer1, buffer2, buffer_size));
-        }
-      }
-
-      // Checking writes at the end of the file.
-      memcpy(buffer + file_size - buffer_size, buffer1, buffer_size);
-      file->Flush();
-      file->Read(buffer2, buffer_size, file_size - buffer_size);
-      EXPECT_EQ(0, strncmp(buffer1, buffer2, buffer_size));
-      file->Flush();
-
-      EXPECT_EQ(file_size, file->GetLength());
-    }
-  }
-}