Revert of Move net::FormatUrl and friends outside of //net and into //components

components/url_fixer/url_fixer.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 "components/url_fixer/url_fixer.h"
+
+#include <algorithm>
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/logging.h"
+#if defined(OS_POSIX)
+#include "base/path_service.h"
+#endif
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "net/base/escape.h"
+#include "net/base/filename_util.h"
+#include "net/base/net_util.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "url/third_party/mozilla/url_parse.h"
+#include "url/url_file.h"
+#include "url/url_util.h"
+
+const char* url_fixer::home_directory_override = NULL;
+
+namespace {
+
+// Hardcode these constants to avoid dependences on //chrome and //content.
+const char kChromeUIScheme[] = "chrome";
+const char kChromeUIDefaultHost[] = "version";
+const char kViewSourceScheme[] = "view-source";
+
+// TODO(estade): Remove these ugly, ugly functions. They are only used in
+// SegmentURL. A url::Parsed object keeps track of a bunch of indices into
+// a url string, and these need to be updated when the URL is converted from
+// UTF8 to UTF16. Instead of this after-the-fact adjustment, we should parse it
+// in the correct string format to begin with.
+url::Component UTF8ComponentToUTF16Component(
+    const std::string& text_utf8,
+    const url::Component& component_utf8) {
+  if (component_utf8.len == -1)
+    return url::Component();
+
+  std::string before_component_string =
+      text_utf8.substr(0, component_utf8.begin);
+  std::string component_string =
+      text_utf8.substr(component_utf8.begin, component_utf8.len);
+  base::string16 before_component_string_16 =
+      base::UTF8ToUTF16(before_component_string);
+  base::string16 component_string_16 = base::UTF8ToUTF16(component_string);
+  url::Component component_16(before_component_string_16.length(),
+                              component_string_16.length());
+  return component_16;
+}
+
+void UTF8PartsToUTF16Parts(const std::string& text_utf8,
+                           const url::Parsed& parts_utf8,
+                           url::Parsed* parts) {
+  if (base::IsStringASCII(text_utf8)) {
+    *parts = parts_utf8;
+    return;
+  }
+
+  parts->scheme = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.scheme);
+  parts->username =
+      UTF8ComponentToUTF16Component(text_utf8, parts_utf8.username);
+  parts->password =
+      UTF8ComponentToUTF16Component(text_utf8, parts_utf8.password);
+  parts->host = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.host);
+  parts->port = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.port);
+  parts->path = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.path);
+  parts->query = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.query);
+  parts->ref = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.ref);
+}
+
+base::TrimPositions TrimWhitespaceUTF8(const std::string& input,
+                                       base::TrimPositions positions,
+                                       std::string* output) {
+  // This implementation is not so fast since it converts the text encoding
+  // twice. Please feel free to file a bug if this function hurts the
+  // performance of Chrome.
+  DCHECK(base::IsStringUTF8(input));
+  base::string16 input16 = base::UTF8ToUTF16(input);
+  base::string16 output16;
+  base::TrimPositions result =
+      base::TrimWhitespace(input16, positions, &output16);
+  *output = base::UTF16ToUTF8(output16);
+  return result;
+}
+
+// does some basic fixes for input that we want to test for file-ness
+void PrepareStringForFileOps(const base::FilePath& text,
+                             base::FilePath::StringType* output) {
+#if defined(OS_WIN)
+  base::TrimWhitespace(text.value(), base::TRIM_ALL, output);
+  replace(output->begin(), output->end(), '/', '\\');
+#else
+  TrimWhitespaceUTF8(text.value(), base::TRIM_ALL, output);
+#endif
+}
+
+// Tries to create a full path from |text|.  If the result is valid and the
+// file exists, returns true and sets |full_path| to the result.  Otherwise,
+// returns false and leaves |full_path| unchanged.
+bool ValidPathForFile(const base::FilePath::StringType& text,
+                      base::FilePath* full_path) {
+  base::FilePath file_path = base::MakeAbsoluteFilePath(base::FilePath(text));
+  if (file_path.empty())
+    return false;
+
+  if (!base::PathExists(file_path))
+    return false;
+
+  *full_path = file_path;
+  return true;
+}
+
+#if defined(OS_POSIX)
+// Given a path that starts with ~, return a path that starts with an
+// expanded-out /user/foobar directory.
+std::string FixupHomedir(const std::string& text) {
+  DCHECK(text.length() > 0 && text[0] == '~');
+
+  if (text.length() == 1 || text[1] == '/') {
+    base::FilePath file_path;
+    if (url_fixer::home_directory_override)
+      file_path = base::FilePath(url_fixer::home_directory_override);
+    else
+      PathService::Get(base::DIR_HOME, &file_path);
+
+    // We'll probably break elsewhere if $HOME is undefined, but check here
+    // just in case.
+    if (file_path.value().empty())
+      return text;
+    // Append requires to be a relative path, so we have to cut all preceeding
+    // '/' characters.
+    size_t i = 1;
+    while (i < text.length() && text[i] == '/')
+      ++i;
+    return file_path.Append(text.substr(i)).value();
+  }
+
+// Otherwise, this is a path like ~foobar/baz, where we must expand to
+// user foobar's home directory.  Officially, we should use getpwent(),
+// but that is a nasty blocking call.
+
+#if defined(OS_MACOSX)
+  static const char kHome[] = "/Users/";
+#else
+  static const char kHome[] = "/home/";
+#endif
+  return kHome + text.substr(1);
+}
+#endif
+
+// Tries to create a file: URL from |text| if it looks like a filename, even if
+// it doesn't resolve as a valid path or to an existing file.  Returns a
+// (possibly invalid) file: URL in |fixed_up_url| for input beginning
+// with a drive specifier or "\\".  Returns the unchanged input in other cases
+// (including file: URLs: these don't look like filenames).
+std::string FixupPath(const std::string& text) {
+  DCHECK(!text.empty());
+
+  base::FilePath::StringType filename;
+#if defined(OS_WIN)
+  base::FilePath input_path(base::UTF8ToWide(text));
+  PrepareStringForFileOps(input_path, &filename);
+
+  // Fixup Windows-style drive letters, where "C:" gets rewritten to "C|".
+  if (filename.length() > 1 && filename[1] == '|')
+    filename[1] = ':';
+#elif defined(OS_POSIX)
+  base::FilePath input_path(text);
+  PrepareStringForFileOps(input_path, &filename);
+  if (filename.length() > 0 && filename[0] == '~')
+    filename = FixupHomedir(filename);
+#endif
+
+  // Here, we know the input looks like a file.
+  GURL file_url = net::FilePathToFileURL(base::FilePath(filename));
+  if (file_url.is_valid()) {
+    return base::UTF16ToUTF8(net::FormatUrl(file_url,
+                                            std::string(),
+                                            net::kFormatUrlOmitUsernamePassword,
+                                            net::UnescapeRule::NORMAL,
+                                            NULL,
+                                            NULL,
+                                            NULL));
+  }
+
+  // Invalid file URL, just return the input.
+  return text;
+}
+
+// Checks |domain| to see if a valid TLD is already present.  If not, appends
+// |desired_tld| to the domain, and prepends "www." unless it's already present.
+void AddDesiredTLD(const std::string& desired_tld, std::string* domain) {
+  if (desired_tld.empty() || domain->empty())
+    return;
+
+  // Check the TLD.  If the return value is positive, we already have a TLD, so
+  // abort.  If the return value is std::string::npos, there's no valid host,
+  // but we can try to append a TLD anyway, since the host may become valid once
+  // the TLD is attached -- for example, "999999999999" is detected as a broken
+  // IP address and marked invalid, but attaching ".com" makes it legal.  When
+  // the return value is 0, there's a valid host with no known TLD, so we can
+  // definitely append the user's TLD.  We disallow unknown registries here so
+  // users can input "mail.yahoo" and hit ctrl-enter to get
+  // "www.mail.yahoo.com".
+  const size_t registry_length =
+      net::registry_controlled_domains::GetRegistryLength(
+          *domain,
+          net::registry_controlled_domains::EXCLUDE_UNKNOWN_REGISTRIES,
+          net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
+  if ((registry_length != 0) && (registry_length != std::string::npos))
+    return;
+
+  // Add the suffix at the end of the domain.
+  const size_t domain_length(domain->length());
+  DCHECK_GT(domain_length, 0U);
+  DCHECK_NE(desired_tld[0], '.');
+  if ((*domain)[domain_length - 1] != '.')
+    domain->push_back('.');
+  domain->append(desired_tld);
+
+  // Now, if the domain begins with "www.", stop.
+  const std::string prefix("www.");
+  if (domain->compare(0, prefix.length(), prefix) != 0) {
+    // Otherwise, add www. to the beginning of the URL.
+    domain->insert(0, prefix);
+  }
+}
+
+inline void FixupUsername(const std::string& text,
+                          const url::Component& part,
+                          std::string* url) {
+  if (!part.is_valid())
+    return;
+
+  // We don't fix up the username at the moment.
+  url->append(text, part.begin, part.len);
+  // Do not append the trailing '@' because we might need to include the user's
+  // password.  FixupURL itself will append the '@' for us.
+}
+
+inline void FixupPassword(const std::string& text,
+                          const url::Component& part,
+                          std::string* url) {
+  if (!part.is_valid())
+    return;
+
+  // We don't fix up the password at the moment.
+  url->append(":");
+  url->append(text, part.begin, part.len);
+}
+
+void FixupHost(const std::string& text,
+               const url::Component& part,
+               bool has_scheme,
+               const std::string& desired_tld,
+               std::string* url) {
+  if (!part.is_valid())
+    return;
+
+  // Make domain valid.
+  // Strip all leading dots and all but one trailing dot, unless the user only
+  // typed dots, in which case their input is totally invalid and we should just
+  // leave it unchanged.
+  std::string domain(text, part.begin, part.len);
+  const size_t first_nondot(domain.find_first_not_of('.'));
+  if (first_nondot != std::string::npos) {
+    domain.erase(0, first_nondot);
+    size_t last_nondot(domain.find_last_not_of('.'));
+    DCHECK(last_nondot != std::string::npos);
+    last_nondot += 2;  // Point at second period in ending string
+    if (last_nondot < domain.length())
+      domain.erase(last_nondot);
+  }
+
+  // Add any user-specified TLD, if applicable.
+  AddDesiredTLD(desired_tld, &domain);
+
+  url->append(domain);
+}
+
+void FixupPort(const std::string& text,
+               const url::Component& part,
+               std::string* url) {
+  if (!part.is_valid())
+    return;
+
+  // We don't fix up the port at the moment.
+  url->append(":");
+  url->append(text, part.begin, part.len);
+}
+
+inline void FixupPath(const std::string& text,
+                      const url::Component& part,
+                      std::string* url) {
+  if (!part.is_valid() || part.len == 0) {
+    // We should always have a path.
+    url->append("/");
+    return;
+  }
+
+  // Append the path as is.
+  url->append(text, part.begin, part.len);
+}
+
+inline void FixupQuery(const std::string& text,
+                       const url::Component& part,
+                       std::string* url) {
+  if (!part.is_valid())
+    return;
+
+  // We don't fix up the query at the moment.
+  url->append("?");
+  url->append(text, part.begin, part.len);
+}
+
+inline void FixupRef(const std::string& text,
+                     const url::Component& part,
+                     std::string* url) {
+  if (!part.is_valid())
+    return;
+
+  // We don't fix up the ref at the moment.
+  url->append("#");
+  url->append(text, part.begin, part.len);
+}
+
+bool HasPort(const std::string& original_text,
+             const url::Component& scheme_component) {
+  // Find the range between the ":" and the "/".
+  size_t port_start = scheme_component.end() + 1;
+  size_t port_end = port_start;
+  while ((port_end < original_text.length()) &&
+         !url::IsAuthorityTerminator(original_text[port_end]))
+    ++port_end;
+  if (port_end == port_start)
+    return false;
+
+  // Scan the range to see if it is entirely digits.
+  for (size_t i = port_start; i < port_end; ++i) {
+    if (!base::IsAsciiDigit(original_text[i]))
+      return false;
+  }
+
+  return true;
+}
+
+// Try to extract a valid scheme from the beginning of |text|.
+// If successful, set |scheme_component| to the text range where the scheme
+// was located, and fill |canon_scheme| with its canonicalized form.
+// Otherwise, return false and leave the outputs in an indeterminate state.
+bool GetValidScheme(const std::string& text,
+                    url::Component* scheme_component,
+                    std::string* canon_scheme) {
+  canon_scheme->clear();
+
+  // Locate everything up to (but not including) the first ':'
+  if (!url::ExtractScheme(
+          text.data(), static_cast<int>(text.length()), scheme_component)) {
+    return false;
+  }
+
+  // Make sure the scheme contains only valid characters, and convert
+  // to lowercase.  This also catches IPv6 literals like [::1], because
+  // brackets are not in the whitelist.
+  url::StdStringCanonOutput canon_scheme_output(canon_scheme);
+  url::Component canon_scheme_component;
+  if (!url::CanonicalizeScheme(text.data(),
+                               *scheme_component,
+                               &canon_scheme_output,
+                               &canon_scheme_component)) {
+    return false;
+  }
+
+  // Strip the ':', and any trailing buffer space.
+  DCHECK_EQ(0, canon_scheme_component.begin);
+  canon_scheme->erase(canon_scheme_component.len);
+
+  // We need to fix up the segmentation for "www.example.com:/".  For this
+  // case, we guess that schemes with a "." are not actually schemes.
+  if (canon_scheme->find('.') != std::string::npos)
+    return false;
+
+  // We need to fix up the segmentation for "www:123/".  For this case, we
+  // will add an HTTP scheme later and make the URL parser happy.
+  // TODO(pkasting): Maybe we should try to use GURL's parser for this?
+  if (HasPort(text, *scheme_component))
+    return false;
+
+  // Everything checks out.
+  return true;
+}
+
+// Performs the work for url_fixer::SegmentURL. |text| may be modified on
+// output on success: a semicolon following a valid scheme is replaced with a
+// colon.
+std::string SegmentURLInternal(std::string* text, url::Parsed* parts) {
+  // Initialize the result.
+  *parts = url::Parsed();
+
+  std::string trimmed;
+  TrimWhitespaceUTF8(*text, base::TRIM_ALL, &trimmed);
+  if (trimmed.empty())
+    return std::string();  // Nothing to segment.
+
+#if defined(OS_WIN)
+  int trimmed_length = static_cast<int>(trimmed.length());
+  if (url::DoesBeginWindowsDriveSpec(trimmed.data(), 0, trimmed_length) ||
+      url::DoesBeginUNCPath(trimmed.data(), 0, trimmed_length, true))
+    return "file";
+#elif defined(OS_POSIX)
+  if (base::FilePath::IsSeparator(trimmed.data()[0]) ||
+      trimmed.data()[0] == '~')
+    return "file";
+#endif
+
+  // Otherwise, we need to look at things carefully.
+  std::string scheme;
+  if (!GetValidScheme(*text, &parts->scheme, &scheme)) {
+    // Try again if there is a ';' in the text. If changing it to a ':' results
+    // in a scheme being found, continue processing with the modified text.
+    bool found_scheme = false;
+    size_t semicolon = text->find(';');
+    if (semicolon != 0 && semicolon != std::string::npos) {
+      (*text)[semicolon] = ':';
+      if (GetValidScheme(*text, &parts->scheme, &scheme))
+        found_scheme = true;
+      else
+        (*text)[semicolon] = ';';
+    }
+    if (!found_scheme) {
+      // Couldn't determine the scheme, so just pick one.
+      parts->scheme.reset();
+      scheme = base::StartsWith(*text, "ftp.",
+                                base::CompareCase::INSENSITIVE_ASCII) ?
+          url::kFtpScheme : url::kHttpScheme;
+    }
+  }
+
+  // Proceed with about and chrome schemes, but not file or nonstandard schemes.
+  if ((scheme != url::kAboutScheme) && (scheme != kChromeUIScheme) &&
+      ((scheme == url::kFileScheme) ||
+       !url::IsStandard(
+           scheme.c_str(),
+           url::Component(0, static_cast<int>(scheme.length()))))) {
+    return scheme;
+  }
+
+  if (scheme == url::kFileSystemScheme) {
+    // Have the GURL parser do the heavy lifting for us.
+    url::ParseFileSystemURL(
+        text->data(), static_cast<int>(text->length()), parts);
+    return scheme;
+  }
+
+  if (parts->scheme.is_valid()) {
+    // Have the GURL parser do the heavy lifting for us.
+    url::ParseStandardURL(
+        text->data(), static_cast<int>(text->length()), parts);
+    return scheme;
+  }
+
+  // We need to add a scheme in order for ParseStandardURL to be happy.
+  // Find the first non-whitespace character.
+  std::string::iterator first_nonwhite = text->begin();
+  while ((first_nonwhite != text->end()) &&
+         base::IsUnicodeWhitespace(*first_nonwhite))
+    ++first_nonwhite;
+
+  // Construct the text to parse by inserting the scheme.
+  std::string inserted_text(scheme);
+  inserted_text.append(url::kStandardSchemeSeparator);
+  std::string text_to_parse(text->begin(), first_nonwhite);
+  text_to_parse.append(inserted_text);
+  text_to_parse.append(first_nonwhite, text->end());
+
+  // Have the GURL parser do the heavy lifting for us.
+  url::ParseStandardURL(
+      text_to_parse.data(), static_cast<int>(text_to_parse.length()), parts);
+
+  // Offset the results of the parse to match the original text.
+  const int offset = -static_cast<int>(inserted_text.length());
+  url_fixer::OffsetComponent(offset, &parts->scheme);
+  url_fixer::OffsetComponent(offset, &parts->username);
+  url_fixer::OffsetComponent(offset, &parts->password);
+  url_fixer::OffsetComponent(offset, &parts->host);
+  url_fixer::OffsetComponent(offset, &parts->port);
+  url_fixer::OffsetComponent(offset, &parts->path);
+  url_fixer::OffsetComponent(offset, &parts->query);
+  url_fixer::OffsetComponent(offset, &parts->ref);
+
+  return scheme;
+}
+
+}  // namespace
+
+std::string url_fixer::SegmentURL(const std::string& text, url::Parsed* parts) {
+  std::string mutable_text(text);
+  return SegmentURLInternal(&mutable_text, parts);
+}
+
+base::string16 url_fixer::SegmentURL(const base::string16& text,
+                                     url::Parsed* parts) {
+  std::string text_utf8 = base::UTF16ToUTF8(text);
+  url::Parsed parts_utf8;
+  std::string scheme_utf8 = SegmentURL(text_utf8, &parts_utf8);
+  UTF8PartsToUTF16Parts(text_utf8, parts_utf8, parts);
+  return base::UTF8ToUTF16(scheme_utf8);
+}
+
+GURL url_fixer::FixupURL(const std::string& text,
+                         const std::string& desired_tld) {
+  std::string trimmed;
+  TrimWhitespaceUTF8(text, base::TRIM_ALL, &trimmed);
+  if (trimmed.empty())
+    return GURL();  // Nothing here.
+
+  // Segment the URL.
+  url::Parsed parts;
+  std::string scheme(SegmentURLInternal(&trimmed, &parts));
+
+  // For view-source: URLs, we strip "view-source:", do fixup, and stick it back
+  // on.  This allows us to handle things like "view-source:google.com".
+  if (scheme == kViewSourceScheme) {
+    // Reject "view-source:view-source:..." to avoid deep recursion.
+    std::string view_source(kViewSourceScheme + std::string(":"));
+    if (!base::StartsWith(text, view_source + view_source,
+                          base::CompareCase::INSENSITIVE_ASCII)) {
+      return GURL(kViewSourceScheme + std::string(":") +
+                  FixupURL(trimmed.substr(scheme.length() + 1), desired_tld)
+                      .possibly_invalid_spec());
+    }
+  }
+
+  // We handle the file scheme separately.
+  if (scheme == url::kFileScheme)
+    return GURL(parts.scheme.is_valid() ? text : FixupPath(text));
+
+  // We handle the filesystem scheme separately.
+  if (scheme == url::kFileSystemScheme) {
+    if (parts.inner_parsed() && parts.inner_parsed()->scheme.is_valid())
+      return GURL(text);
+    return GURL();
+  }
+
+  // Parse and rebuild about: and chrome: URLs, except about:blank.
+  bool chrome_url =
+      !base::LowerCaseEqualsASCII(trimmed, url::kAboutBlankURL) &&
+      ((scheme == url::kAboutScheme) || (scheme == kChromeUIScheme));
+
+  // For some schemes whose layouts we understand, we rebuild it.
+  if (chrome_url ||
+      url::IsStandard(scheme.c_str(),
+                      url::Component(0, static_cast<int>(scheme.length())))) {
+    // Replace the about: scheme with the chrome: scheme.
+    std::string url(chrome_url ? kChromeUIScheme : scheme);
+    url.append(url::kStandardSchemeSeparator);
+
+    // We need to check whether the |username| is valid because it is our
+    // responsibility to append the '@' to delineate the user information from
+    // the host portion of the URL.
+    if (parts.username.is_valid()) {
+      FixupUsername(trimmed, parts.username, &url);
+      FixupPassword(trimmed, parts.password, &url);
+      url.append("@");
+    }
+
+    FixupHost(trimmed, parts.host, parts.scheme.is_valid(), desired_tld, &url);
+    if (chrome_url && !parts.host.is_valid())
+      url.append(kChromeUIDefaultHost);
+    FixupPort(trimmed, parts.port, &url);
+    FixupPath(trimmed, parts.path, &url);
+    FixupQuery(trimmed, parts.query, &url);
+    FixupRef(trimmed, parts.ref, &url);
+
+    return GURL(url);
+  }
+
+  // In the worst-case, we insert a scheme if the URL lacks one.
+  if (!parts.scheme.is_valid()) {
+    std::string fixed_scheme(scheme);
+    fixed_scheme.append(url::kStandardSchemeSeparator);
+    trimmed.insert(0, fixed_scheme);
+  }
+
+  return GURL(trimmed);
+}
+
+// The rules are different here than for regular fixup, since we need to handle
+// input like "hello.html" and know to look in the current directory.  Regular
+// fixup will look for cues that it is actually a file path before trying to
+// figure out what file it is.  If our logic doesn't work, we will fall back on
+// regular fixup.
+GURL url_fixer::FixupRelativeFile(const base::FilePath& base_dir,
+                                  const base::FilePath& text) {
+  base::FilePath old_cur_directory;
+  if (!base_dir.empty()) {
+    // Save the old current directory before we move to the new one.
+    base::GetCurrentDirectory(&old_cur_directory);
+    base::SetCurrentDirectory(base_dir);
+  }
+
+  // Allow funny input with extra whitespace and the wrong kind of slashes.
+  base::FilePath::StringType trimmed;
+  PrepareStringForFileOps(text, &trimmed);
+
+  bool is_file = true;
+  // Avoid recognizing definite non-file URLs as file paths.
+  GURL gurl(trimmed);
+  if (gurl.is_valid() && gurl.IsStandard())
+    is_file = false;
+  base::FilePath full_path;
+  if (is_file && !ValidPathForFile(trimmed, &full_path)) {
+// Not a path as entered, try unescaping it in case the user has
+// escaped things. We need to go through 8-bit since the escaped values
+// only represent 8-bit values.
+#if defined(OS_WIN)
+    std::wstring unescaped = base::UTF8ToWide(net::UnescapeURLComponent(
+        base::WideToUTF8(trimmed),
+        net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS));
+#elif defined(OS_POSIX)
+    std::string unescaped = net::UnescapeURLComponent(
+        trimmed,
+        net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
+#endif
+
+    if (!ValidPathForFile(unescaped, &full_path))
+      is_file = false;
+  }
+
+  // Put back the current directory if we saved it.
+  if (!base_dir.empty())
+    base::SetCurrentDirectory(old_cur_directory);
+
+  if (is_file) {
+    GURL file_url = net::FilePathToFileURL(full_path);
+    if (file_url.is_valid())
+      return GURL(
+          base::UTF16ToUTF8(net::FormatUrl(file_url,
+                                           std::string(),
+                                           net::kFormatUrlOmitUsernamePassword,
+                                           net::UnescapeRule::NORMAL,
+                                           NULL,
+                                           NULL,
+                                           NULL)));
+    // Invalid files fall through to regular processing.
+  }
+
+// Fall back on regular fixup for this input.
+#if defined(OS_WIN)
+  std::string text_utf8 = base::WideToUTF8(text.value());
+#elif defined(OS_POSIX)
+  std::string text_utf8 = text.value();
+#endif
+  return FixupURL(text_utf8, std::string());
+}
+
+void url_fixer::OffsetComponent(int offset, url::Component* part) {
+  DCHECK(part);
+
+  if (part->is_valid()) {
+    // Offset the location of this component.
+    part->begin += offset;
+
+    // This part might not have existed in the original text.
+    if (part->begin < 0)
+      part->reset();
+  }
+}
+
+bool url_fixer::IsEquivalentScheme(const std::string& scheme1,
+                                   const std::string& scheme2) {
+  return scheme1 == scheme2 ||
+      (scheme1 == url::kAboutScheme && scheme2 == kChromeUIScheme) ||
+      (scheme1 == kChromeUIScheme && scheme2 == url::kAboutScheme);
+}