Reorganize CommandLine code.

The majority of these changes are purely moving code.
Conducted some minor (and hopefully straightforward) refactoring.

BUG=73195
TEST=none

Review URL: http://codereview.chromium.org/6596020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@76339 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 297 insertions, 344 deletions

diff --git a/base/command_line.cc b/base/command_line.cc
index c0a0f19..eefd6ac 100644
--- a/base/command_line.cc
+++ b/base/command_line.cc
@@ -27,31 +27,29 @@
 
 CommandLine* CommandLine::current_process_commandline_ = NULL;
 
-// Since we use a lazy match, make sure that longer versions (like L"--")
-// are listed before shorter versions (like L"-") of similar prefixes.
+namespace {
+typedef CommandLine::StringType::value_type CharType;
+
+const CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
+const CharType kSwitchValueSeparator[] = FILE_PATH_LITERAL("=");
+// Since we use a lazy match, make sure that longer versions (like "--") are
+// listed before shorter versions (like "-") of similar prefixes.
 #if defined(OS_WIN)
-const wchar_t* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
-const wchar_t kSwitchTerminator[] = L"--";
-const wchar_t kSwitchValueSeparator[] = L"=";
+const CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
 #elif defined(OS_POSIX)
 // Unixes don't use slash as a switch.
-const char* const kSwitchPrefixes[] = {"--", "-"};
-const char kSwitchTerminator[] = "--";
-const char kSwitchValueSeparator[] = "=";
+const CharType* const kSwitchPrefixes[] = {"--", "-"};
 #endif
 
 #if defined(OS_WIN)
-namespace {
-// Lowercase a string.  This is used to lowercase switch names.
-// Is this what we really want?  It seems crazy to me.  I've left it in
-// for backwards compatibility on Windows.
-void Lowercase(std::string* parameter) {
-  transform(parameter->begin(), parameter->end(), parameter->begin(),
-            tolower);
+// Lowercase a string for case-insensitivity of switches.
+// Is this desirable? It exists for backwards compatibility on Windows.
+void Lowercase(std::string* arg) {
+  transform(arg->begin(), arg->end(), arg->begin(), tolower);
 }
 
-// Quote a string if necessary, such that CommandLineToArgvW() will
-// always process it as a single argument.
+// Quote a string if necessary, such that CommandLineToArgvW() will always
+// process it as a single argument.
 std::wstring WindowsStyleQuote(const std::wstring& arg) {
   // We follow the quoting rules of CommandLineToArgvW.
   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
@@ -93,94 +91,117 @@ std::wstring WindowsStyleQuote(const std::wstring& arg) {
 
   return out;
 }
-}  // namespace
 #endif
 
-CommandLine::~CommandLine() {
-}
-
-#if defined(OS_WIN)
-CommandLine::CommandLine(NoProgram no_program) {
-}
-
-void CommandLine::ParseFromString(const std::wstring& command_line) {
-  TrimWhitespace(command_line, TRIM_ALL, &command_line_string_);
-
-  if (command_line_string_.empty())
-    return;
-
-  int num_args = 0;
-  wchar_t** args = NULL;
-
-  args = CommandLineToArgvW(command_line_string_.c_str(), &num_args);
-
-  // Populate program_ with the trimmed version of the first arg.
-  TrimWhitespace(args[0], TRIM_ALL, &program_);
-
-  bool parse_switches = true;
-  for (int i = 1; i < num_args; ++i) {
-    std::wstring arg;
-    TrimWhitespace(args[i], TRIM_ALL, &arg);
-
-    if (!parse_switches) {
-      args_.push_back(arg);
-      continue;
-    }
+// Returns true and fills in |switch_string| and |switch_value| if
+// |parameter_string| represents a switch.
+bool IsSwitch(const CommandLine::StringType& parameter_string,
+              std::string* switch_string,
+              CommandLine::StringType* switch_value) {
+  switch_string->clear();
+  switch_value->clear();
 
-    if (arg == kSwitchTerminator) {
-      parse_switches = false;
+  for (size_t i = 0; i < arraysize(kSwitchPrefixes); ++i) {
+    CommandLine::StringType prefix(kSwitchPrefixes[i]);
+    if (parameter_string.find(prefix) != 0)
       continue;
-    }
 
-    std::string switch_string;
-    std::wstring switch_value;
-    if (IsSwitch(arg, &switch_string, &switch_value)) {
-      switches_[switch_string] = switch_value;
+    const size_t switch_start = prefix.length();
+    const size_t equals_position = parameter_string.find(
+        kSwitchValueSeparator, switch_start);
+    CommandLine::StringType switch_native;
+    if (equals_position == CommandLine::StringType::npos) {
+      switch_native = parameter_string.substr(switch_start);
     } else {
-      args_.push_back(arg);
+      switch_native = parameter_string.substr(
+          switch_start, equals_position - switch_start);
+      *switch_value = parameter_string.substr(equals_position + 1);
     }
+#if defined(OS_WIN)
+    *switch_string = WideToASCII(switch_native);
+    Lowercase(switch_string);
+#else
+    *switch_string = switch_native;
+#endif
+
+    return true;
   }
 
-  if (args)
-    LocalFree(args);
+  return false;
 }
 
-// static
-CommandLine CommandLine::FromString(const std::wstring& command_line) {
-  CommandLine cmd;
-  cmd.ParseFromString(command_line);
-  return cmd;
+}  // namespace
+
+CommandLine::CommandLine(NoProgram no_program) {
+#if defined(OS_POSIX)
+  // Push an empty argument, because we always assume argv_[0] is a program.
+  argv_.push_back("");
+#endif
 }
 
 CommandLine::CommandLine(const FilePath& program) {
+#if defined(OS_WIN)
   if (!program.empty()) {
     program_ = program.value();
     // TODO(evanm): proper quoting here.
     command_line_string_ = L'"' + program.value() + L'"';
   }
-}
-
 #elif defined(OS_POSIX)
-CommandLine::CommandLine(NoProgram no_program) {
-  // Push an empty argument, because we always assume argv_[0] is a program.
-  argv_.push_back("");
+  argv_.push_back(program.value());
+#endif
 }
 
+#if defined(OS_POSIX)
 CommandLine::CommandLine(int argc, const char* const* argv) {
   InitFromArgv(argc, argv);
 }
 
-CommandLine::CommandLine(const std::vector<std::string>& argv) {
+CommandLine::CommandLine(const StringVector& argv) {
   InitFromArgv(argv);
 }
+#endif  // OS_POSIX
 
+// static
+void CommandLine::Init(int argc, const char* const* argv) {
+  delete current_process_commandline_;
+  current_process_commandline_ = new CommandLine;
+#if defined(OS_WIN)
+  current_process_commandline_->ParseFromString(::GetCommandLineW());
+#elif defined(OS_POSIX)
+  current_process_commandline_->InitFromArgv(argc, argv);
+#endif
+}
+
+// static
+void CommandLine::Reset() {
+  DCHECK(current_process_commandline_);
+  delete current_process_commandline_;
+  current_process_commandline_ = NULL;
+}
+
+// static
+CommandLine* CommandLine::ForCurrentProcess() {
+  DCHECK(current_process_commandline_);
+  return current_process_commandline_;
+}
+
+#if defined(OS_WIN)
+// static
+CommandLine CommandLine::FromString(const std::wstring& command_line) {
+  CommandLine cmd;
+  cmd.ParseFromString(command_line);
+  return cmd;
+}
+#endif  // OS_WIN
+
+#if defined(OS_POSIX)
 void CommandLine::InitFromArgv(int argc, const char* const* argv) {
   for (int i = 0; i < argc; ++i)
     argv_.push_back(argv[i]);
   InitFromArgv(argv_);
 }
 
-void CommandLine::InitFromArgv(const std::vector<std::string>& argv) {
+void CommandLine::InitFromArgv(const StringVector& argv) {
   argv_ = argv;
   bool parse_switches = true;
   for (size_t i = 1; i < argv_.size(); ++i) {
@@ -197,7 +218,7 @@ void CommandLine::InitFromArgv(const std::vector<std::string>& argv) {
     }
 
     std::string switch_string;
-    std::string switch_value;
+    StringType switch_value;
     if (IsSwitch(arg, &switch_string, &switch_value)) {
       switches_[switch_string] = switch_value;
     } else {
@@ -205,72 +226,25 @@ void CommandLine::InitFromArgv(const std::vector<std::string>& argv) {
     }
   }
 }
+#endif  // OS_POSIX
 
-CommandLine::CommandLine(const FilePath& program) {
-  argv_.push_back(program.value());
-}
-
-#endif
-
-// static
-bool CommandLine::IsSwitch(const StringType& parameter_string,
-                           std::string* switch_string,
-                           StringType* switch_value) {
-  switch_string->clear();
-  switch_value->clear();
-
-  for (size_t i = 0; i < arraysize(kSwitchPrefixes); ++i) {
-    StringType prefix(kSwitchPrefixes[i]);
-    if (parameter_string.find(prefix) != 0)
-      continue;
-
-    const size_t switch_start = prefix.length();
-    const size_t equals_position = parameter_string.find(
-        kSwitchValueSeparator, switch_start);
-    StringType switch_native;
-    if (equals_position == StringType::npos) {
-      switch_native = parameter_string.substr(switch_start);
-    } else {
-      switch_native = parameter_string.substr(
-          switch_start, equals_position - switch_start);
-      *switch_value = parameter_string.substr(equals_position + 1);
-    }
+CommandLine::StringType CommandLine::command_line_string() const {
 #if defined(OS_WIN)
-    *switch_string = WideToASCII(switch_native);
-    Lowercase(switch_string);
-#else
-    *switch_string = switch_native;
+  return command_line_string_;
+#elif defined(OS_POSIX)
+  return JoinString(argv_, ' ');
 #endif
-
-    return true;
-  }
-
-  return false;
 }
 
-// static
-void CommandLine::Init(int argc, const char* const* argv) {
-  delete current_process_commandline_;
-  current_process_commandline_ = new CommandLine;
+FilePath CommandLine::GetProgram() const {
 #if defined(OS_WIN)
-  current_process_commandline_->ParseFromString(::GetCommandLineW());
-#elif defined(OS_POSIX)
-  current_process_commandline_->InitFromArgv(argc, argv);
+  return FilePath(program_);
+#else
+  DCHECK_GT(argv_.size(), 0U);
+  return FilePath(argv_[0]);
 #endif
 }
 
-void CommandLine::Reset() {
-  DCHECK(current_process_commandline_ != NULL);
-  delete current_process_commandline_;
-  current_process_commandline_ = NULL;
-}
-
-// static
-CommandLine* CommandLine::ForCurrentProcess() {
-  DCHECK(current_process_commandline_);
-  return current_process_commandline_;
-}
-
 bool CommandLine::HasSwitch(const std::string& switch_string) const {
   std::string lowercased_switch(switch_string);
 #if defined(OS_WIN)
@@ -305,8 +279,7 @@ CommandLine::StringType CommandLine::GetSwitchValueNative(
   Lowercase(&lowercased_switch);
 #endif
 
-  std::map<std::string, StringType>::const_iterator result =
-      switches_.find(lowercased_switch);
+  SwitchMap::const_iterator result = switches_.find(lowercased_switch);
 
   if (result == switches_.end()) {
     return CommandLine::StringType();
@@ -315,31 +288,30 @@ CommandLine::StringType CommandLine::GetSwitchValueNative(
   }
 }
 
-FilePath CommandLine::GetProgram() const {
-#if defined(OS_WIN)
-  return FilePath(program_);
-#else
-  DCHECK_GT(argv_.size(), 0U);
-  return FilePath(argv_[0]);
-#endif
-}
-
-#if defined(OS_POSIX)
-std::string CommandLine::command_line_string() const {
-  return JoinString(argv_, ' ');
+size_t CommandLine::GetSwitchCount() const {
+  return switches_.size();
 }
-#endif
 
-#if defined(OS_WIN)
 void CommandLine::AppendSwitch(const std::string& switch_string) {
+#if defined(OS_WIN)
   command_line_string_.append(L" ");
   command_line_string_.append(kSwitchPrefixes[0] + ASCIIToWide(switch_string));
   switches_[switch_string] = L"";
+#elif defined(OS_POSIX)
+  argv_.push_back(kSwitchPrefixes[0] + switch_string);
+  switches_[switch_string] = "";
+#endif
+}
+
+void CommandLine::AppendSwitchPath(const std::string& switch_string,
+                                   const FilePath& path) {
+  AppendSwitchNative(switch_string, path.value());
 }
 
 void CommandLine::AppendSwitchNative(const std::string& switch_string,
-                                     const std::wstring& value) {
-  std::wstring combined_switch_string =
+                                     const CommandLine::StringType& value) {
+#if defined(OS_WIN)
+  StringType combined_switch_string =
       kSwitchPrefixes[0] + ASCIIToWide(switch_string);
   if (!value.empty())
     combined_switch_string += kSwitchValueSeparator + WindowsStyleQuote(value);
@@ -348,26 +320,79 @@ void CommandLine::AppendSwitchNative(const std::string& switch_string,
   command_line_string_.append(combined_switch_string);
 
   switches_[switch_string] = value;
+#elif defined(OS_POSIX)
+  StringType combined_switch_string = kSwitchPrefixes[0] + switch_string;
+  if (!value.empty())
+    combined_switch_string += kSwitchValueSeparator + value;
+  argv_.push_back(combined_switch_string);
+  switches_[switch_string] = value;
+#endif
 }
 
 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
                                     const std::string& value_string) {
+#if defined(OS_WIN)
   AppendSwitchNative(switch_string, ASCIIToWide(value_string));
+#elif defined(OS_POSIX)
+  AppendSwitchNative(switch_string, value_string);
+#endif
+}
+
+void CommandLine::AppendSwitches(const CommandLine& other) {
+  SwitchMap::const_iterator i;
+  for (i = other.switches_.begin(); i != other.switches_.end(); ++i)
+    AppendSwitchNative(i->first, i->second);
+}
+
+void CommandLine::CopySwitchesFrom(const CommandLine& source,
+                                   const char* const switches[],
+                                   size_t count) {
+  for (size_t i = 0; i < count; ++i) {
+    if (source.HasSwitch(switches[i])) {
+      StringType value = source.GetSwitchValueNative(switches[i]);
+      AppendSwitchNative(switches[i], value);
+    }
+  }
 }
 
 void CommandLine::AppendArg(const std::string& value) {
+#if defined(OS_WIN)
   DCHECK(IsStringUTF8(value));
   AppendArgNative(UTF8ToWide(value));
+#elif defined(OS_POSIX)
+  AppendArgNative(value);
+#endif
 }
 
-void CommandLine::AppendArgNative(const std::wstring& value) {
+void CommandLine::AppendArgPath(const FilePath& path) {
+  AppendArgNative(path.value());
+}
+
+void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
+#if defined(OS_WIN)
   command_line_string_.append(L" ");
   command_line_string_.append(WindowsStyleQuote(value));
   args_.push_back(value);
+#elif defined(OS_POSIX)
+  DCHECK(IsStringUTF8(value));
+  argv_.push_back(value);
+#endif
+}
+
+void CommandLine::AppendArgs(const CommandLine& other) {
+  if(other.args_.size() <= 0)
+    return;
+#if defined(OS_WIN)
+  command_line_string_.append(L" --");
+#endif  // OS_WIN
+  StringVector::const_iterator i;
+  for (i = other.args_.begin(); i != other.args_.end(); ++i)
+    AppendArgNative(*i);
 }
 
 void CommandLine::AppendArguments(const CommandLine& other,
                                   bool include_program) {
+#if defined(OS_WIN)
   // Verify include_program is used correctly.
   DCHECK(!include_program || !other.GetProgram().empty());
   if (include_program)
@@ -377,54 +402,7 @@ void CommandLine::AppendArguments(const CommandLine& other,
     command_line_string_ += L' ';
 
   command_line_string_ += other.command_line_string_;
-
-  std::map<std::string, StringType>::const_iterator i;
-  for (i = other.switches_.begin(); i != other.switches_.end(); ++i)
-    switches_[i->first] = i->second;
-}
-
-void CommandLine::PrependWrapper(const std::wstring& wrapper) {
-  if (wrapper.empty())
-    return;
-  // The wrapper may have embedded arguments (like "gdb --args"). In this case,
-  // we don't pretend to do anything fancy, we just split on spaces.
-  std::vector<std::wstring> wrapper_and_args;
-  base::SplitString(wrapper, ' ', &wrapper_and_args);
-  program_ = wrapper_and_args[0];
-  command_line_string_ = wrapper + L" " + command_line_string_;
-}
-
 #elif defined(OS_POSIX)
-void CommandLine::AppendSwitch(const std::string& switch_string) {
-  argv_.push_back(kSwitchPrefixes[0] + switch_string);
-  switches_[switch_string] = "";
-}
-
-void CommandLine::AppendSwitchNative(const std::string& switch_string,
-                                     const std::string& value) {
-  std::string combined_switch_string = kSwitchPrefixes[0] + switch_string;
-  if (!value.empty())
-    combined_switch_string += kSwitchValueSeparator + value;
-  argv_.push_back(combined_switch_string);
-  switches_[switch_string] = value;
-}
-
-void CommandLine::AppendSwitchASCII(const std::string& switch_string,
-                                    const std::string& value_string) {
-  AppendSwitchNative(switch_string, value_string);
-}
-
-void CommandLine::AppendArg(const std::string& value) {
-  AppendArgNative(value);
-}
-
-void CommandLine::AppendArgNative(const std::string& value) {
-  DCHECK(IsStringUTF8(value));
-  argv_.push_back(value);
-}
-
-void CommandLine::AppendArguments(const CommandLine& other,
-                                  bool include_program) {
   // Verify include_program is used correctly.
   // Logic could be shorter but this is clearer.
   DCHECK_EQ(include_program, !other.GetProgram().empty());
@@ -436,66 +414,69 @@ void CommandLine::AppendArguments(const CommandLine& other,
   // arguments to our arg vector.
   for (size_t i = 1; i < other.argv_.size(); ++i)
     argv_.push_back(other.argv_[i]);
+#endif
 
-  std::map<std::string, StringType>::const_iterator i;
+  SwitchMap::const_iterator i;
   for (i = other.switches_.begin(); i != other.switches_.end(); ++i)
     switches_[i->first] = i->second;
 }
 
-void CommandLine::PrependWrapper(const std::string& wrapper) {
+void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
   // we don't pretend to do anything fancy, we just split on spaces.
-  std::vector<std::string> wrapper_and_args;
+  if (wrapper.empty())
+    return;
+  StringVector wrapper_and_args;
+#if defined(OS_WIN)
+  base::SplitString(wrapper, ' ', &wrapper_and_args);
+  program_ = wrapper_and_args[0];
+  command_line_string_ = wrapper + L" " + command_line_string_;
+#elif defined(OS_POSIX)
   base::SplitString(wrapper, ' ', &wrapper_and_args);
   argv_.insert(argv_.begin(), wrapper_and_args.begin(), wrapper_and_args.end());
+#endif
 }
 
-#endif
+#if defined(OS_WIN)
+void CommandLine::ParseFromString(const std::wstring& command_line) {
+  TrimWhitespace(command_line, TRIM_ALL, &command_line_string_);
 
-void CommandLine::AppendSwitchPath(const std::string& switch_string,
-                                   const FilePath& path) {
-  AppendSwitchNative(switch_string, path.value());
-}
+  if (command_line_string_.empty())
+    return;
 
-void CommandLine::AppendSwitches(const CommandLine& other) {
-  std::map<std::string, StringType>::const_iterator i;
-  for (i = other.switches_.begin(); i != other.switches_.end(); ++i)
-    AppendSwitchNative(i->first, i->second);
-}
+  int num_args = 0;
+  wchar_t** args = NULL;
 
-void CommandLine::AppendArgPath(const FilePath& path) {
-  AppendArgNative(path.value());
-}
+  args = CommandLineToArgvW(command_line_string_.c_str(), &num_args);
 
-void CommandLine::AppendArgs(const CommandLine& other) {
-  if(other.args_.size() <= 0)
-    return;
+  // Populate program_ with the trimmed version of the first arg.
+  TrimWhitespace(args[0], TRIM_ALL, &program_);
 
-#if defined(OS_WIN)
-  command_line_string_.append(L" --");
-#endif  // OS_WIN
-  std::vector<StringType>::const_iterator i;
-  for (i = other.args_.begin(); i != other.args_.end(); ++i)
-    AppendArgNative(*i);
-}
+  bool parse_switches = true;
+  for (int i = 1; i < num_args; ++i) {
+    std::wstring arg;
+    TrimWhitespace(args[i], TRIM_ALL, &arg);
 
-void CommandLine::CopySwitchesFrom(const CommandLine& source,
-                                   const char* const switches[],
-                                   size_t count) {
-  for (size_t i = 0; i < count; ++i) {
-    if (source.HasSwitch(switches[i])) {
-      StringType value = source.GetSwitchValueNative(switches[i]);
-      AppendSwitchNative(switches[i], value);
+    if (!parse_switches) {
+      args_.push_back(arg);
+      continue;
     }
-  }
-}
 
-// private
-CommandLine::CommandLine() {
-}
+    if (arg == kSwitchTerminator) {
+      parse_switches = false;
+      continue;
+    }
 
-// static
-CommandLine* CommandLine::ForCurrentProcessMutable() {
-  DCHECK(current_process_commandline_);
-  return current_process_commandline_;
+    std::string switch_string;
+    std::wstring switch_value;
+    if (IsSwitch(arg, &switch_string, &switch_value)) {
+      switches_[switch_string] = switch_value;
+    } else {
+      args_.push_back(arg);
+    }
+  }
+
+  if (args)
+    LocalFree(args);
 }
+#endif
diff --git a/base/command_line.h b/base/command_line.h
index db61458..a6313ee 100644
--- a/base/command_line.h
+++ b/base/command_line.h
@@ -3,15 +3,13 @@
 // found in the LICENSE file.
 
 // This class works with command lines: building and parsing.
-// Switches can optionally have a value attached using an equals sign,
-// as in "-switch=value".  Arguments that aren't prefixed with a
-// switch prefix are saved as extra arguments.  An argument of "--"
-// will terminate switch parsing, causing everything after to be
-// considered as extra arguments.
+// Switches can optionally have a value attached using an equals sign, as in
+// "-switch=value". Arguments that aren't prefixed with a switch prefix are
+// saved as extra arguments. An argument of "--" will terminate switch parsing,
+// causing everything after to be considered as extra arguments.
 
-// There is a singleton read-only CommandLine that represents the command
-// line that the current process was started with.  It must be initialized
-// in main() (or whatever the platform's equivalent function is).
+// There is a singleton read-only CommandLine that represents the command line
+// that the current process was started with.  It must be initialized in main().
 
 #ifndef BASE_COMMAND_LINE_H_
 #define BASE_COMMAND_LINE_H_
@@ -25,111 +23,91 @@
 #include "build/build_config.h"
 
 class FilePath;
-class InProcessBrowserTest;
 
 class CommandLine {
  public:
 #if defined(OS_WIN)
-  // The type of native command line arguments.
+  // The native command line string type.
   typedef std::wstring StringType;
 #elif defined(OS_POSIX)
-  // The type of native command line arguments.
   typedef std::string StringType;
 #endif
 
+  typedef std::vector<StringType> StringVector;
   // The type of map for parsed-out switch key and values.
   typedef std::map<std::string, StringType> SwitchMap;
 
-  // A constructor for CommandLines that are used only to carry switches and
-  // arguments.
+  // A constructor for CommandLines that only carry switches and arguments.
   enum NoProgram { NO_PROGRAM };
   explicit CommandLine(NoProgram no_program);
 
-  // Construct a new, empty command line.
-  // |program| is the name of the program to run (aka argv[0]).
+  // Construct a new command line with |program| as argv[0].
   explicit CommandLine(const FilePath& program);
 
 #if defined(OS_POSIX)
   CommandLine(int argc, const char* const* argv);
-  explicit CommandLine(const std::vector<std::string>& argv);
+  explicit CommandLine(const StringVector& argv);
 #endif
 
-  ~CommandLine();
-
-#if defined(OS_WIN)
-  // Initialize by parsing the given command-line string.
-  // The program name is assumed to be the first item in the string.
-  void ParseFromString(const std::wstring& command_line);
-  static CommandLine FromString(const std::wstring& command_line);
-#elif defined(OS_POSIX)
-  // Initialize from an argv vector.
-  void InitFromArgv(int argc, const char* const* argv);
-  void InitFromArgv(const std::vector<std::string>& argv);
-#endif
-
-  // Initialize the current process CommandLine singleton.  On Windows,
-  // ignores its arguments (we instead parse GetCommandLineW()
-  // directly) because we don't trust the CRT's parsing of the command
-  // line, but it still must be called to set up the command line.
+  // Initialize the current process CommandLine singleton. On Windows, ignores
+  // its arguments (we instead parse GetCommandLineW() directly) because we
+  // don't trust the CRT's parsing of the command line, but it still must be
+  // called to set up the command line.
   static void Init(int argc, const char* const* argv);
 
   // Destroys the current process CommandLine singleton. This is necessary if
-  // you want to reset the base library to its initial state (for example in an
+  // you want to reset the base library to its initial state (for example, in an
   // outer library that needs to be able to terminate, and be re-initialized).
-  // If Init is called only once, e.g. in main(), calling Reset() is not
-  // necessary.
+  // If Init is called only once, as in main(), Reset() is not necessary.
   static void Reset();
 
   // Get the singleton CommandLine representing the current process's
-  // command line.  Note: returned value is mutable, but not thread safe;
+  // command line. Note: returned value is mutable, but not thread safe;
   // only mutate if you know what you're doing!
   static CommandLine* ForCurrentProcess();
 
+#if defined(OS_WIN)
+  static CommandLine FromString(const std::wstring& command_line);
+#endif
+
+#if defined(OS_POSIX)
+  // Initialize from an argv vector.
+  void InitFromArgv(int argc, const char* const* argv);
+  void InitFromArgv(const StringVector& argv);
+#endif
+
+  // Returns the represented command line string.
+  // CAUTION! This should be avoided because quoting behavior is unclear.
+  StringType command_line_string() const;
+
+#if defined(OS_POSIX)
+  // Returns the original command line string as a vector of strings.
+  const StringVector& argv() const { return argv_; }
+#endif
+
+  // Returns the program part of the command line string (the first item).
+  FilePath GetProgram() const;
+
   // Returns true if this command line contains the given switch.
-  // (Switch names are case-insensitive.)
+  // (Switch names are case-insensitive).
   bool HasSwitch(const std::string& switch_string) const;
 
-  // Returns the value associated with the given switch.  If the
-  // switch has no value or isn't present, this method returns
-  // the empty string.
+  // Returns the value associated with the given switch. If the switch has no
+  // value or isn't present, this method returns the empty string.
   std::string GetSwitchValueASCII(const std::string& switch_string) const;
   FilePath GetSwitchValuePath(const std::string& switch_string) const;
   StringType GetSwitchValueNative(const std::string& switch_string) const;
 
   // Get the number of switches in this process.
-  size_t GetSwitchCount() const { return switches_.size(); }
+  // TODO(msw): Remove unnecessary API.
+  size_t GetSwitchCount() const;
 
-  // Get a copy of all switches, along with their values
-  const SwitchMap& GetSwitches() const {
-    return switches_;
-  }
+  // Get a copy of all switches, along with their values.
+  const SwitchMap& GetSwitches() const { return switches_; }
 
-  // Get the remaining arguments to the command.
-  const std::vector<StringType>& args() const { return args_; }
-
-#if defined(OS_WIN)
-  // Returns the original command line string.
-  const std::wstring& command_line_string() const {
-    return command_line_string_;
-  }
-#elif defined(OS_POSIX)
-  // Returns the original command line string as a vector of strings.
-  const std::vector<std::string>& argv() const {
-    return argv_;
-  }
-  // Try to match the same result as command_line_string() would get you
-  // on windows.
-  std::string command_line_string() const;
-#endif
-
-  // Returns the program part of the command line string (the first item).
-  FilePath GetProgram() const;
-
-  // Append a switch to the command line.
+  // Append a switch [with optional value] to the command line.
+  // CAUTION! Appending a switch after the "--" switch terminator is futile!
   void AppendSwitch(const std::string& switch_string);
-
-  // Append a switch and value to the command line.
-  // CAUTION! Appending a switch after the "--" kSwitchTerminator is futile!
   void AppendSwitchPath(const std::string& switch_string, const FilePath& path);
   void AppendSwitchNative(const std::string& switch_string,
                           const StringType& value);
@@ -137,11 +115,17 @@ class CommandLine {
                          const std::string& value);
   void AppendSwitches(const CommandLine& other);
 
-  // Append an argument to the command line.
-  // Note on quoting: the argument will be quoted properly such that it is
-  // interpreted as one argument to the target command.
-  // AppendArg is primarily for ASCII; non-ASCII input will be
-  // interpreted as UTF-8.
+  // Copy a set of switches (and any values) from another command line.
+  // Commonly used when launching a subprocess.
+  void CopySwitchesFrom(const CommandLine& source, const char* const switches[],
+                        size_t count);
+
+  // Get the remaining arguments to the command.
+  const StringVector& args() const { return args_; }
+
+  // Append an argument to the command line. Note that the argument is quoted
+  // properly such that it is interpreted as one argument to the target command.
+  // AppendArg is primarily for ASCII; non-ASCII input is interpreted as UTF-8.
   void AppendArg(const std::string& value);
   void AppendArgPath(const FilePath& value);
   void AppendArgNative(const StringType& value);
@@ -152,55 +136,43 @@ class CommandLine {
   void AppendArguments(const CommandLine& other,
                        bool include_program);
 
-  // Insert a command before the current command.  Common for debuggers,
-  // like "valgrind" or "gdb --args".
+  // Insert a command before the current command.
+  // Common for debuggers, like "valgrind" or "gdb --args".
   void PrependWrapper(const StringType& wrapper);
 
-  // Copy a set of switches (and their values, if any) from another command
-  // line.  Commonly used when launching a subprocess.
-  void CopySwitchesFrom(const CommandLine& source, const char* const switches[],
-                        size_t count);
+#if defined(OS_WIN)
+  // Initialize by parsing the given command line string.
+  // The program name is assumed to be the first item in the string.
+  void ParseFromString(const std::wstring& command_line);
+#endif
 
  private:
-  friend class InProcessBrowserTest;
-
-  CommandLine();
+  // Disallow default constructor; a program name must be explicitly specified.
+  CommandLine() {}
 
-  // Used by InProcessBrowserTest.
-  static CommandLine* ForCurrentProcessMutable();
-
-  // Returns true and fills in |switch_string| and |switch_value|
-  // if |parameter_string| represents a switch.
-  static bool IsSwitch(const StringType& parameter_string,
-                       std::string* switch_string,
-                       StringType* switch_value);
-
-  // The singleton CommandLine instance representing the current process's
-  // command line.
+  // The singleton CommandLine representing the current process's command line.
   static CommandLine* current_process_commandline_;
 
   // We store a platform-native version of the command line, used when building
-  // up a new command line to be executed.  This ifdef delimits that code.
-
+  // up a new command line to be executed. This ifdef delimits that code.
 #if defined(OS_WIN)
-  // The quoted, space-separated command-line string.
-  std::wstring command_line_string_;
+  // The quoted, space-separated command line string.
+  StringType command_line_string_;
   // The name of the program.
-  std::wstring program_;
+  StringType program_;
 #elif defined(OS_POSIX)
   // The argv array, with the program name in argv_[0].
-  std::vector<std::string> argv_;
+  StringVector argv_;
 #endif
 
-  // Parsed-out values.
+  // Parsed-out switch keys and values.
   SwitchMap switches_;
 
-  // Non-switch command-line arguments.
-  std::vector<StringType> args_;
+  // Non-switch command line arguments.
+  StringVector args_;
 
-  // We allow copy constructors, because a common pattern is to grab a
-  // copy of the current process's command line and then add some
-  // flags to it.  E.g.:
+  // Allow the copy constructor. A common pattern is to copy the current
+  // process's command line and then add some flags to it. For example:
   //   CommandLine cl(*CommandLine::ForCurrentProcess());
   //   cl.AppendSwitch(...);
 };