Revert of [Courgette] Adding CourgetteConfig singleton and --experimental flag. (patchset #5 id:80001 of https://chromiumcodereview.appspot.com/1306193004/ )

Reason for revert:
The original CL assumes Courgette had to deal with forward/backward compatibility issues.
Turns out that (as seen in http://crbug.com/459505):
- Courgette executable is shipped with new releases.
- This allows Courgette workflow to proceed without being tied down to legacy.

These new (to huangs@) facts render the original CL redundant.

Original issue's description:
> [Courgette] Adding CourgetteConfig singleton and --experimental flag.
>
> This prepare for upcoming experiments to reduce patch size. We want to
> avoid disrupting existing functionality.
>
> Committed: https://crrev.com/fc0511d9067759336f42d04e918e8a3ce0b84376
> Cr-Commit-Position: refs/heads/master@{#346746}

TBR=wfh@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1323263007

Cr-Commit-Position: refs/heads/master@{#347746}

7 files changed, 4 insertions, 93 deletions

diff --git a/courgette/BUILD.gn b/courgette/BUILD.gn
index 2deef9c2..1ebd2ee 100644
--- a/courgette/BUILD.gn
+++ b/courgette/BUILD.gn
@@ -12,8 +12,6 @@ static_library("courgette_lib") {
     "assembly_program.cc",
     "assembly_program.h",
     "courgette.h",
-    "courgette_config.cc",
-    "courgette_config.h",
     "crc.cc",
     "crc.h",
     "difference_estimator.cc",
diff --git a/courgette/courgette.gyp b/courgette/courgette.gyp
index 5ece6e9..8ff08bc 100644
--- a/courgette/courgette.gyp
+++ b/courgette/courgette.gyp
@@ -12,8 +12,6 @@
       'assembly_program.cc',
       'assembly_program.h',
       'courgette.h',
-      'courgette_config.cc',
-      'courgette_config.h',
       'crc.cc',
       'crc.h',
       'difference_estimator.cc',
diff --git a/courgette/courgette_config.cc b/courgette/courgette_config.cc
deleted file mode 100644
index b92e43a..0000000
--- a/courgette/courgette_config.cc
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright 2015 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 "courgette/courgette_config.h"
-
-#include "base/command_line.h"
-#include "courgette/ensemble.h"
-
-namespace courgette {
-
-namespace {
-
-static const uint32 kExperimentalVersion = 0xDEADBEEF;
-
-}  // namespace
-
-// static
-CourgetteConfig* CourgetteConfig::GetInstance() {
-  return Singleton<CourgetteConfig>::get();
-}
-
-uint32 CourgetteConfig::ensemble_version() const {
-  return is_experimental_ ? kExperimentalVersion : CourgettePatchFile::kVersion;
-}
-
-void CourgetteConfig::Initialize(const base::CommandLine& command_line) {
-  is_experimental_ = command_line.HasSwitch("experimental");
-}
-
-CourgetteConfig::CourgetteConfig() : is_experimental_(false) {
-}
-
-}  // namespace courgette
diff --git a/courgette/courgette_config.h b/courgette/courgette_config.h
deleted file mode 100644
index cbcfc22..0000000
--- a/courgette/courgette_config.h
+++ /dev/null
@@ -1,39 +0,0 @@
-// Copyright 2015 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 COURGETTE_COURGETTE_CONFIG_H_
-#define COURGETTE_COURGETTE_CONFIG_H_
-
-#include "base/macros.h"
-#include "base/memory/singleton.h"
-
-namespace base {
-class CommandLine;
-}  // namespace base
-
-namespace courgette {
-
-// A singleton class to hold global configurations for Courgette, mainly for
-// experimental purposes.
-class CourgetteConfig {
- public:
-  static CourgetteConfig* GetInstance();
-
-  void Initialize(const base::CommandLine& command_line);
-
-  bool is_experimental() const { return is_experimental_; }
-
-  uint32 ensemble_version() const;
-
- private:
-  bool is_experimental_;
-
-  CourgetteConfig();
-
-  friend struct DefaultSingletonTraits<CourgetteConfig>;
-};
-
-}  // namespace courgette
-
-#endif  // COURGETTE_COURGETTE_CONFIG_H_
diff --git a/courgette/courgette_tool.cc b/courgette/courgette_tool.cc
index eb3e823..962e078 100644
--- a/courgette/courgette_tool.cc
+++ b/courgette/courgette_tool.cc
@@ -15,7 +15,6 @@
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "courgette/courgette.h"
-#include "courgette/courgette_config.h"
 #include "courgette/streams.h"
 #include "courgette/third_party/bsdiff.h"
 
@@ -430,7 +429,6 @@ int main(int argc, const char* argv[]) {
   base::CommandLine::Init(argc, argv);
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
-  courgette::CourgetteConfig::GetInstance()->Initialize(command_line);
 
   logging::LoggingSettings settings;
   settings.logging_dest = logging::LOG_TO_ALL;
@@ -472,10 +470,6 @@ int main(int argc, const char* argv[]) {
         "  -supported -asm, -dis, -disadj, -gen or -apply, -genbsdiff"
         " or -applybsdiff.");
 
-  if (courgette::CourgetteConfig::GetInstance()->is_experimental()) {
-    fprintf(stderr, "Experimental flag enabled. Do not use in production.\n");
-  }
-
   while (repeat_count-- > 0) {
     if (cmd_sup) {
       if (values.size() != 1)
diff --git a/courgette/ensemble_apply.cc b/courgette/ensemble_apply.cc
index 62297fd..121fae8 100644
--- a/courgette/ensemble_apply.cc
+++ b/courgette/ensemble_apply.cc
@@ -10,7 +10,6 @@
 #include "base/files/file_util.h"
 #include "base/files/memory_mapped_file.h"
 #include "base/logging.h"
-#include "courgette/courgette_config.h"
 #include "courgette/crc.h"
 #include "courgette/patcher_x86_32.h"
 #include "courgette/region.h"
@@ -97,9 +96,7 @@ Status EnsemblePatchApplication::ReadHeader(SourceStream* header_stream) {
   if (!header_stream->ReadVarint32(&version))
     return C_BAD_ENSEMBLE_VERSION;
 
-  uint32 expected_ensemble_version =
-      CourgetteConfig::GetInstance()->ensemble_version();
-  if (version != expected_ensemble_version)
+  if (version != CourgettePatchFile::kVersion)
     return C_BAD_ENSEMBLE_VERSION;
 
   if (!header_stream->ReadVarint32(&source_checksum_))
@@ -429,4 +426,4 @@ Status ApplyEnsemblePatch(const base::FilePath::CharType* old_file_name,
   return C_OK;
 }
 
-}  // namespace courgette
+}  // namespace
diff --git a/courgette/ensemble_create.cc b/courgette/ensemble_create.cc
index a0c2e0b..ea5873c 100644
--- a/courgette/ensemble_create.cc
+++ b/courgette/ensemble_create.cc
@@ -21,7 +21,6 @@
 #include "base/logging.h"
 #include "base/time/time.h"
 
-#include "courgette/courgette_config.h"
 #include "courgette/crc.h"
 #include "courgette/difference_estimator.h"
 #include "courgette/region.h"
@@ -436,10 +435,8 @@ Status GenerateEnsemblePatch(SourceStream* base,
   //
   // Final output stream has a header followed by a StreamSet.
   //
-  uint32 ensemble_version =
-      CourgetteConfig::GetInstance()->ensemble_version();
   if (!final_patch->WriteVarint32(CourgettePatchFile::kMagic) ||
-      !final_patch->WriteVarint32(ensemble_version) ||
+      !final_patch->WriteVarint32(CourgettePatchFile::kVersion) ||
       !final_patch->WriteVarint32(CalculateCrc(old_region.start(),
                                                old_region.length())) ||
       !final_patch->WriteVarint32(CalculateCrc(new_region.start(),
@@ -455,4 +452,4 @@ Status GenerateEnsemblePatch(SourceStream* base,
   return C_OK;
 }
 
-}  // namespace courgette
+}  // namespace