Removing fragmentation checker implementation.

The fragmentation checker was added to test whether manually defragmenting chrome.dll would help very many users. Over 94% of users have chrome.dll taking up a single extent so it appears that manual defragging won't help much. Removing the implementation.

BUG=98033
TEST=NONE


Review URL: http://codereview.chromium.org/9222005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119081 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 0 insertions, 174 deletions

diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 94676d5..7952244 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -146,7 +146,6 @@
 #include "chrome/browser/chrome_browser_main_win.h"
 #include "chrome/browser/first_run/try_chrome_dialog_view.h"
 #include "chrome/browser/first_run/upgrade_util_win.h"
-#include "chrome/browser/fragmentation_checker_win.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/rlz/rlz.h"
 #include "chrome/browser/ui/views/user_data_dir_dialog.h"
@@ -1670,10 +1669,6 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
   LanguageUsageMetrics::RecordApplicationLanguage(
       browser_process_->GetApplicationLocale());
 
-#if defined(OS_WIN)
-  fragmentation_checker::RecordFragmentationMetricForCurrentModule();
-#endif
-
   // The extension service may be available at this point. If the command line
   // specifies --uninstall-extension, attempt the uninstall extension startup
   // action.
diff --git a/chrome/browser/fragmentation_checker_unittest_win.cc b/chrome/browser/fragmentation_checker_unittest_win.cc
deleted file mode 100644
index c778d76..0000000
--- a/chrome/browser/fragmentation_checker_unittest_win.cc
+++ /dev/null
@@ -1,24 +0,0 @@
-// 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/file_path.h"
-#include "base/path_service.h"
-#include "chrome/browser/fragmentation_checker_win.h"
-#include "chrome/common/guid.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-TEST(FragmentationChecker, BasicCheck) {
-  FilePath module_path;
-  ASSERT_TRUE(PathService::Get(base::FILE_MODULE, &module_path));
-  int extent_count = fragmentation_checker::CountFileExtents(module_path);
-  EXPECT_GT(extent_count, 0);
-}
-
-TEST(FragmentationChecker, InvalidFile) {
-  FilePath module_path;
-  ASSERT_TRUE(PathService::Get(base::FILE_MODULE, &module_path));
-  module_path = module_path.DirName().AppendASCII(guid::GenerateGUID());
-  int extent_count = fragmentation_checker::CountFileExtents(module_path);
-  EXPECT_EQ(extent_count, 0);
-}
diff --git a/chrome/browser/fragmentation_checker_win.cc b/chrome/browser/fragmentation_checker_win.cc
deleted file mode 100644
index 04d4ac6..0000000
--- a/chrome/browser/fragmentation_checker_win.cc
+++ /dev/null
@@ -1,114 +0,0 @@
-// 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 "chrome/browser/fragmentation_checker_win.h"
-
-#include <windows.h>
-#include <winioctl.h>
-
-#include <vector>
-
-#include "base/file_path.h"
-#include "base/logging.h"
-#include "base/metrics/histogram.h"
-#include "base/platform_file.h"
-#include "base/path_service.h"
-
-namespace {
-
-size_t ComputeRetrievalPointersBufferSize(int number_of_extents) {
-  // We make a redundant access to buffer.ExtentCount (which is always 0) below
-  // to avoid C4101 on MSVC2010.
-  RETRIEVAL_POINTERS_BUFFER buffer = {0};
-  return sizeof(buffer) + (number_of_extents - 1) * sizeof(buffer.Extents) +
-      buffer.ExtentCount;
-}
-
-}  // namespace
-
-namespace fragmentation_checker {
-
-int CountFileExtents(const FilePath& file_path) {
-  int file_extents_count = 0;
-
-  base::PlatformFileError error_code = base::PLATFORM_FILE_ERROR_FAILED;
-  base::PlatformFile file_handle = CreatePlatformFile(
-      file_path,
-      base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ,
-      NULL,
-      &error_code);
-  if (error_code == base::PLATFORM_FILE_OK) {
-    STARTING_VCN_INPUT_BUFFER starting_vcn_input_buffer = {0};
-
-    // Compute an output size capable of holding 16 extents at first. This will
-    // fail when the number of extents exceeds 16, in which case we make
-    // a bigger buffer capable of holding up to kMaxExtentCounts.
-    int extents_guess = 16;
-    size_t output_size = ComputeRetrievalPointersBufferSize(extents_guess);
-    std::vector<uint8> retrieval_pointers_buffer(output_size);
-
-    DWORD bytes_returned = 0;
-
-    bool result = false;
-    do {
-      result = DeviceIoControl(
-          file_handle,
-          FSCTL_GET_RETRIEVAL_POINTERS,
-          reinterpret_cast<void*>(&starting_vcn_input_buffer),
-          sizeof(starting_vcn_input_buffer),
-          reinterpret_cast<void*>(&retrieval_pointers_buffer[0]),
-          retrieval_pointers_buffer.size(),
-          &bytes_returned,
-          NULL) != FALSE;
-
-      if (!result) {
-        if (GetLastError() == ERROR_MORE_DATA) {
-          // Grow the extents we can handle
-          extents_guess *= 2;
-          if (extents_guess > kMaxExtentCount) {
-            LOG(ERROR) << "FSCTL_GET_RETRIEVAL_POINTERS output buffer exceeded "
-                          "maximum size.";
-            file_extents_count = kMaxExtentCount;
-            break;
-          }
-          output_size = ComputeRetrievalPointersBufferSize(extents_guess);
-          retrieval_pointers_buffer.assign(output_size, 0);
-        } else {
-          PLOG(ERROR) << "FSCTL_GET_RETRIEVAL_POINTERS failed.";
-          break;
-        }
-      }
-    } while (!result);
-
-    if (result) {
-      RETRIEVAL_POINTERS_BUFFER* retrieval_pointers =
-          reinterpret_cast<RETRIEVAL_POINTERS_BUFFER*>(
-              &retrieval_pointers_buffer[0]);
-      file_extents_count = static_cast<int>(retrieval_pointers->ExtentCount);
-    } else {
-      LOG(ERROR) << "Failed to retrieve extents.";
-    }
-  } else {
-    LOG(ERROR) << "Failed to open module file to check extents. Error code = "
-               << error_code;
-  }
-
-  return file_extents_count;
-}
-
-void RecordFragmentationMetricForCurrentModule() {
-  FilePath module_path;
-  if (PathService::Get(base::FILE_MODULE, &module_path)) {
-    int file_extent_count = CountFileExtents(module_path);
-    UMA_HISTOGRAM_CUSTOM_COUNTS("Fragmentation.ModuleExtents",
-                                file_extent_count,
-                                0,
-                                kMaxExtentCount,
-                                50);
-  } else {
-    NOTREACHED() << "Could not get path to current module.";
-  }
-}
-
-}  // namespace fragmentation_checker
diff --git a/chrome/browser/fragmentation_checker_win.h b/chrome/browser/fragmentation_checker_win.h
deleted file mode 100644
index 02f4231..0000000
--- a/chrome/browser/fragmentation_checker_win.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// 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.
-
-#ifndef CHROME_BROWSER_FRAGMENTATION_CHECKER_WIN_H_
-#define CHROME_BROWSER_FRAGMENTATION_CHECKER_WIN_H_
-#pragma once
-
-class FilePath;
-
-namespace fragmentation_checker {
-
-const int kMaxExtentCount = 1 << 16;
-
-// Returns the number of extents for the file at |file_path|. The number is
-// capped at kMaxExtentCount, files with more extents than that will be counted
-// as having kMaxExtentCount extents. On failure, this function returns 0.
-int CountFileExtents(const FilePath& file_path);
-
-// Records fragmentation metrics for the current module. This records the number
-// of fragments the current module is stored in.
-// This will be used to determine whether pursuing more aggressive
-// manual defragmentation is worth the effort.
-void RecordFragmentationMetricForCurrentModule();
-
-}  // namespace fragmentation_checker
-
-#endif  // CHROME_BROWSER_FRAGMENTATION_CHECKER_WIN_H_
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 0d36d08..293fd95 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1336,8 +1336,6 @@
         'browser/first_run/upgrade_util_mac.cc',
         'browser/first_run/upgrade_util_win.cc',
         'browser/first_run/upgrade_util_win.h',
-        'browser/fragmentation_checker_win.cc',
-        'browser/fragmentation_checker_win.h',
         'browser/fullscreen.h',
         'browser/fullscreen_aura.cc',
         'browser/fullscreen_gtk.cc',
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index cec7fcf..26a88cf 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -1468,7 +1468,6 @@
         'browser/external_protocol/external_protocol_handler_unittest.cc',
         'browser/favicon/favicon_handler_unittest.cc',
         'browser/first_run/first_run_unittest.cc',
-        'browser/fragmentation_checker_unittest_win.cc',
         'browser/geolocation/chrome_geolocation_permission_context_unittest.cc',
         'browser/geolocation/geolocation_settings_state_unittest.cc',
         'browser/geolocation/wifi_data_provider_unittest_chromeos.cc',