Share strings between native and Java

Creates a script that can be used to generate Java files to
expose native strings to Java, giving us a single source of
truth for these constants.

Bug: 937280
Change-Id: I1f0804bdfff8101dfd149612acd44360ae0dc2c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1495747
Commit-Queue: Ian Vollick <vollick@chromium.org>
Auto-Submit: Ian Vollick <vollick@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638754}

PRESUBMIT.py

@@ -678,6 +678,7 @@ _ANDROID_SPECIFIC_PYDEPS_FILES = [
     'build/android/gyp/generate_linker_version_script.pydeps',
     'build/android/gyp/ijar.pydeps',
     'build/android/gyp/java_cpp_enum.pydeps',
+    'build/android/gyp/java_cpp_strings.pydeps',
     'build/android/gyp/javac.pydeps',
     'build/android/gyp/jinja_template.pydeps',
     'build/android/gyp/lint.pydeps',

build/android/gyp/java_cpp_enum.py

@@ -15,6 +15,7 @@ import textwrap
 import zipfile
 
 from util import build_utils
+from util import java_cpp_utils
 
 # List of C++ types that are compatible with the Java code generated by this
 # script.
@@ -115,8 +116,8 @@ class EnumDefinition(object):
     self.comments = StripEntries(self.comments)
 
   def _NormalizeNames(self):
-    self.entries = _TransformKeys(self.entries, _KCamelToShouty)
-    self.comments = _TransformKeys(self.comments, _KCamelToShouty)
+    self.entries = _TransformKeys(self.entries, java_cpp_utils.KCamelToShouty)
+    self.comments = _TransformKeys(self.comments, java_cpp_utils.KCamelToShouty)
 
 
 def _TransformKeys(d, func):
@@ -133,25 +134,6 @@ def _TransformKeys(d, func):
   return ret
 
 
-def _KCamelToShouty(s):
-  """Convert |s| from kCamelCase or CamelCase to SHOUTY_CASE.
-
-  kFooBar -> FOO_BAR
-  FooBar -> FOO_BAR
-  FooBAR9 -> FOO_BAR9
-  FooBARBaz -> FOO_BAR_BAZ
-  """
-  if not re.match(r'^k?([A-Z][^A-Z]+|[A-Z0-9]+)+$', s):
-    return s
-  # Strip the leading k.
-  s = re.sub(r'^k', '', s)
-  # Add _ between title words and anything else.
-  s = re.sub(r'([^_])([A-Z][^A-Z_0-9]+)', r'\1_\2', s)
-  # Add _ between lower -> upper transitions.
-  s = re.sub(r'([^A-Z_0-9])([A-Z])', r'\1_\2', s)
-  return s.upper()
-
-
 class DirectiveSet(object):
   class_name_override_key = 'CLASS_NAME_OVERRIDE'
   enum_package_key = 'ENUM_PACKAGE'
@@ -334,8 +316,6 @@ class HeaderParser(object):
       if single_line_enum:
         self._ParseSingleLineEnum(single_line_enum.group('enum_entries'))
 
-def GetScriptName():
-  return os.path.basename(os.path.abspath(sys.argv[0]))
 
 def DoGenerate(source_paths):
   for source_path in source_paths:
@@ -401,8 +381,8 @@ ${ENUM_ENTRIES}
           subsequent_indent=enum_comments_indent,
           width=100)
       enum_entries_string.append('  /**')
-        enum_entries_string.append(
-                '\n'.join(comments_line_wrapper.wrap(enum_comments)))
+      enum_entries_string.append('\n'.join(
+          comments_line_wrapper.wrap(enum_comments)))
       enum_entries_string.append('   */')
     enum_entries_string.append(enum_template.substitute(values))
     enum_names.append(enum_definition.class_name + '.' + enum_name)
@@ -419,7 +399,7 @@ ${ENUM_ENTRIES}
       'ENUM_ENTRIES': enum_entries_string,
       'PACKAGE': enum_definition.enum_package,
       'INT_DEF': enum_names_string,
-      'SCRIPT_NAME': GetScriptName(),
+      'SCRIPT_NAME': java_cpp_utils.GetScriptName(),
       'SOURCE_PATH': source_path,
       'YEAR': str(date.today().year)
   }

build/android/gyp/java_cpp_enum.pydeps

@@ -4,4 +4,5 @@
 java_cpp_enum.py
 util/__init__.py
 util/build_utils.py
+util/java_cpp_utils.py
 util/md5_check.py

build/android/gyp/java_cpp_enum_tests.py

@@ -5,7 +5,7 @@
 
 """Tests for enum_preprocess.py.
 
-This test suite containss various tests for the C++ -> Java enum generator.
+This test suite contains various tests for the C++ -> Java enum generator.
 """
 
 import collections
@@ -13,8 +13,9 @@ from datetime import date
 import unittest
 
 import java_cpp_enum
-from java_cpp_enum import EnumDefinition, GenerateOutput, GetScriptName
+from java_cpp_enum import EnumDefinition, GenerateOutput
 from java_cpp_enum import HeaderParser
+from util import java_cpp_utils
 
 
 class TestPreprocess(unittest.TestCase):
@@ -65,8 +66,8 @@ public @interface ClassName {
     long_comment = ('This is a multiple line comment that is really long. '
                     'This is a multiple line comment that is')
     self.assertEqual(
-            expected % (date.today().year, GetScriptName(), long_comment),
-            output)
+        expected % (date.today().year, java_cpp_utils.GetScriptName(),
+                    long_comment), output)
 
   def testParseSimpleEnum(self):
     test_data = """

build/android/gyp/java_cpp_strings.py

+#!/user/bin/env python
+#
+# Copyright 2019 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.
+
+import argparse
+import os
+import re
+import sys
+import zipfile
+
+from util import build_utils
+from util import java_cpp_utils
+
+
+def _ToUpper(match):
+  return match.group(1).upper()
+
+
+def _GetClassName(source_path):
+  name = os.path.basename(os.path.abspath(source_path))
+  (name, _) = os.path.splitext(name)
+  name = re.sub(r'_([a-z])', _ToUpper, name)
+  name = re.sub(r'^(.)', _ToUpper, name)
+  return name
+
+
+class _String(object):
+
+  def __init__(self, name, value, comments):
+    self.name = java_cpp_utils.KCamelToShouty(name)
+    self.value = value
+    self.comments = '\n'.join('    ' + x for x in comments)
+
+  def Format(self):
+    return '%s\n    public static final String %s = %s;' % (
+        self.comments, self.name, self.value)
+
+
+def ParseTemplateFile(lines):
+  package_re = re.compile(r'^package (.*);')
+  class_re = re.compile(r'.*class (.*) {')
+  package = ''
+  class_name = ''
+  for line in lines:
+    package_line = package_re.match(line)
+    if package_line:
+      package = package_line.groups()[0]
+    class_line = class_re.match(line)
+    if class_line:
+      class_name = class_line.groups()[0]
+      break
+  return package, class_name
+
+
+# TODO(crbug.com/937282): It should be possible to parse a file for more than
+# string constants. However, this currently only handles extracting string
+# constants from a file (and all string constants from that file). Work will
+# be needed if we want to annotate specific constants or non string constants
+# in the file to be parsed.
+class StringFileParser(object):
+  SINGLE_LINE_COMMENT_RE = re.compile(r'\s*(// [^\n]*)')
+  STRING_RE = re.compile(r'\s*const char k(.*)\[\]\s*=\s*(?:(".*"))?')
+  VALUE_RE = re.compile(r'\s*("[^"]*")')
+
+  def __init__(self, lines, path=''):
+    self._lines = lines
+    self._path = path
+    self._in_string = False
+    self._in_comment = False
+    self._package = ''
+    self._current_comments = []
+    self._current_name = ''
+    self._current_value = ''
+    self._strings = []
+
+  def _Reset(self):
+    self._current_comments = []
+    self._current_name = ''
+    self._current_value = ''
+    self._in_string = False
+    self._in_comment = False
+
+  def _AppendString(self):
+    self._strings.append(
+        _String(self._current_name, self._current_value,
+                self._current_comments))
+    self._Reset()
+
+  def _ParseValue(self, line):
+    value_line = StringFileParser.VALUE_RE.match(line)
+    if value_line:
+      self._current_value = value_line.groups()[0]
+      self._AppendString()
+    else:
+      self._Reset()
+
+  def _ParseComment(self, line):
+    comment_line = StringFileParser.SINGLE_LINE_COMMENT_RE.match(line)
+    if comment_line:
+      self._current_comments.append(comment_line.groups()[0])
+      self._in_comment = True
+      self._in_string = True
+      return True
+    else:
+      self._in_comment = False
+      return False
+
+  def _ParseString(self, line):
+    string_line = StringFileParser.STRING_RE.match(line)
+    if string_line:
+      self._current_name = string_line.groups()[0]
+      if string_line.groups()[1]:
+        self._current_value = string_line.groups()[1]
+        self._AppendString()
+      return True
+    else:
+      self._in_string = False
+      return False
+
+  def _ParseLine(self, line):
+    if not self._in_string:
+      self._ParseComment(line)
+      return
+
+    if self._in_comment:
+      if self._ParseComment(line):
+        return
+      if not self._ParseString(line):
+        self._Reset()
+      return
+
+    if self._in_string:
+      self._ParseValue(line)
+
+  def Parse(self):
+    for line in self._lines:
+      self._ParseLine(line)
+    return self._strings
+
+
+def _GenerateOutput(template, source_path, template_path, strings):
+  description_template = """
+    // This following string constants were inserted by
+    //     {SCRIPT_NAME}
+    // From
+    //     {SOURCE_PATH}
+    // Into
+    //     {TEMPLATE_PATH}
+
+"""
+  values = {
+      'SCRIPT_NAME': java_cpp_utils.GetScriptName(),
+      'SOURCE_PATH': source_path,
+      'TEMPLATE_PATH': template_path,
+  }
+  description = description_template.format(**values)
+  native_strings = '\n\n'.join(x.Format() for x in strings)
+
+  values = {
+      'NATIVE_STRINGS': description + native_strings,
+  }
+  return template.format(**values)
+
+
+def _ParseStringFile(path):
+  with open(path) as f:
+    return StringFileParser(f.readlines(), path).Parse()
+
+
+def _Generate(source_paths, template_path):
+  with open(template_path) as f:
+    lines = f.readlines()
+    template = ''.join(lines)
+    for source_path in source_paths:
+      strings = _ParseStringFile(source_path)
+      package, class_name = ParseTemplateFile(lines)
+      package_path = package.replace('.', os.path.sep)
+      file_name = class_name + '.java'
+      output_path = os.path.join(package_path, file_name)
+      output = _GenerateOutput(template, source_path, template_path, strings)
+      yield output, output_path
+
+
+def _Main(argv):
+  parser = argparse.ArgumentParser()
+
+  parser.add_argument(
+      '--srcjar',
+      required=True,
+      help='When specified, a .srcjar at the given path is '
+      'created instead of individual .java files.')
+
+  parser.add_argument(
+      '--template',
+      required=True,
+      help='Can be used to provide a context into which the'
+      'new string constants will be inserted.')
+
+  parser.add_argument(
+      'inputs', nargs='+', help='Input file(s)', metavar='INPUTFILE')
+  args = parser.parse_args(argv)
+
+  with build_utils.AtomicOutput(args.srcjar) as f:
+    with zipfile.ZipFile(f, 'w', zipfile.ZIP_STORED) as srcjar:
+      for data, path in _Generate(args.inputs, args.template):
+        build_utils.AddToZipHermetic(srcjar, path, data=data)
+
+
+if __name__ == '__main__':
+  _Main(sys.argv[1:])

build/android/gyp/java_cpp_strings.pydeps

+# Generated by running:
+#   build/print_python_deps.py --root build/android/gyp --output build/android/gyp/java_cpp_strings.pydeps build/android/gyp/java_cpp_strings.py
+../../gn_helpers.py
+java_cpp_strings.py
+util/__init__.py
+util/build_utils.py
+util/java_cpp_utils.py
+util/md5_check.py

build/android/gyp/java_cpp_strings_tests.py

+#!/usr/bin/env python
+
+# Copyright 2019 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.
+
+"""Tests for java_cpp_strings.py.
+
+This test suite contains various tests for the C++ -> Java string generator.
+"""
+
+import unittest
+
+import java_cpp_strings
+
+
+class _TestStringsParser(unittest.TestCase):
+
+  def testParseComments(self):
+    test_data = """
+/**
+ * This should be ignored as well.
+ */
+
+// Comment followed by a blank line.
+
+// Comment followed by unrelated code.
+int foo() { return 3; }
+
+// Real comment.
+const char kASwitch[] = "a-value";
+
+// Real comment that spans
+// multiple lines.
+const char kAnotherSwitch[] = "another-value";
+
+// Comment followed by nothing.
+""".split('\n')
+    strings = java_cpp_strings.StringFileParser(test_data).Parse()
+    self.assertEqual(2, len(strings))
+    self.assertEqual('A_SWITCH', strings[0].name)
+    self.assertEqual('"a-value"', strings[0].value)
+    self.assertEqual(1, len(strings[0].comments.split('\n')))
+    self.assertEqual('ANOTHER_SWITCH', strings[1].name)
+    self.assertEqual('"another-value"', strings[1].value)
+    self.assertEqual(2, len(strings[1].comments.split('\n')))
+
+  def testStringValues(self):
+    test_data = """
+// Single line string constants.
+const char kAString[] = "a-value";
+
+// Single line switch with a big space.
+const char kAStringWithSpace[]                      = "a-value";
+
+// Wrapped constant definition.
+const char kAStringWithAVeryLongNameThatWillHaveToWrap[] =
+    "a-string-with-a-very-long-name-that-will-have-to-wrap";
+
+// This is erroneous and should be ignored.
+const char kInvalidLineBreak[] =
+
+    "invalid-line-break";
+""".split('\n')
+    strings = java_cpp_strings.StringFileParser(test_data).Parse()
+    self.assertEqual(3, len(strings))
+    self.assertEqual('A_STRING', strings[0].name)
+    self.assertEqual('"a-value"', strings[0].value)
+    self.assertEqual('A_STRING_WITH_SPACE', strings[1].name)
+    self.assertEqual('"a-value"', strings[1].value)
+    self.assertEqual('A_STRING_WITH_A_VERY_LONG_NAME_THAT_WILL_HAVE_TO_WRAP',
+                     strings[2].name)
+    self.assertEqual('"a-string-with-a-very-long-name-that-will-have-to-wrap"',
+                     strings[2].value)
+
+  def testTemplateParsing(self):
+    test_data = """
+// Copyright {YEAR} 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.
+
+// This file is autogenerated by
+//     {SCRIPT_NAME}
+// From
+//     {SOURCE_PATH}, and
+//     {TEMPLATE_PATH}
+
+package my.java.package;
+
+public any sort of class MyClass {{
+
+{NATIVE_STRINGS}
+
+}}
+""".split('\n')
+    package, class_name = java_cpp_strings.ParseTemplateFile(test_data)
+    self.assertEqual('my.java.package', package)
+    self.assertEqual('MyClass', class_name)
+
+
+if __name__ == '__main__':
+  unittest.main()

build/android/gyp/util/java_cpp_utils.py

+#!/user/bin/env python
+#
+# Copyright 2019 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.
+
+import os
+import re
+import sys
+
+
+def GetScriptName():
+  return os.path.basename(os.path.abspath(sys.argv[0]))
+
+
+def KCamelToShouty(s):
+  """Convert |s| from kCamelCase or CamelCase to SHOUTY_CASE.
+
+  kFooBar -> FOO_BAR
+  FooBar -> FOO_BAR
+  FooBAR9 -> FOO_BAR9
+  FooBARBaz -> FOO_BAR_BAZ
+  """
+  if not re.match(r'^k?([A-Z][^A-Z]+|[A-Z0-9]+)+$', s):
+    return s
+  # Strip the leading k.
+  s = re.sub(r'^k', '', s)
+  # Add _ between title words and anything else.
+  s = re.sub(r'([^_])([A-Z][^A-Z_0-9]+)', r'\1_\2', s)
+  # Add _ between lower -> upper transitions.
+  s = re.sub(r'([^A-Z_0-9])([A-Z])', r'\1_\2', s)
+  return s.upper()

build/android/pylib/constants/__init__.py

@@ -130,7 +130,8 @@ UBSAN_OPTIONS = (
 # TODO(jbudorick): Rework this into testing/buildbot/
 PYTHON_UNIT_TEST_SUITES = {
     'pylib_py_unittests': {
-    'path': os.path.join(DIR_SOURCE_ROOT, 'build', 'android'),
+        'path':
+        os.path.join(DIR_SOURCE_ROOT, 'build', 'android'),
         'test_modules': [
             'devil.android.device_utils_test',
             'devil.android.md5sum_test',
@@ -140,9 +141,11 @@ PYTHON_UNIT_TEST_SUITES = {
         ]
     },
     'gyp_py_unittests': {
-    'path': os.path.join(DIR_SOURCE_ROOT, 'build', 'android', 'gyp'),
+        'path':
+        os.path.join(DIR_SOURCE_ROOT, 'build', 'android', 'gyp'),
         'test_modules': [
             'java_cpp_enum_tests',
+            'java_cpp_strings_tests',
             'java_google_api_keys_tests',
             'extract_unwind_tables_tests',
         ]

build/config/android/rules.gni

@@ -635,6 +635,85 @@ if (enable_java_templates) {
     }
   }
 
+  # Declare a target for generating Java classes with string constants matching
+  # those found in C++ files using a python script.
+  #
+  # This target will create a single .srcjar. Adding this target to an
+  # android_library target's srcjar_deps will make the generated java files be
+  # included in that library's final outputs.
+  #
+  # Variables
+  #   sources: list of files to be processed by the script. For each string
+  #            constant in the source files, the script will add a corresponding
+  #            Java string to the specified template file.
+  # Example
+  #   java_cpp_strings("foo_switches") {
+  #     sources = [
+  #       "src/foo_switches.cc",
+  #     ]
+  #     template = "src/templates/FooSwitches.java.tmpl
+  #   }
+  #
+  # foo_switches.cc:
+  #
+  # // A switch.
+  # const char kASwitch = "a-switch";
+  #
+  # FooSwitches.java.tmpl
+  #
+  # // Copyright {YEAR} 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.
+  #
+  # // This file is autogenerated by
+  # //     {SCRIPT_NAME}
+  # // From
+  # //     {SOURCE_PATH}, and
+  # //     {TEMPLATE_PATH}
+  #
+  # package my.java.package;
+  #
+  # public abstract class FooSwitches {{
+  #     // ...snip...
+  # {NATIVE_STRINGS}
+  #     // ...snip...
+  # }}
+  #
+  # result:
+  #   A FooSwitches.java file, defining a class named FooSwitches in the package
+  #   my.java.package.
+  template("java_cpp_strings") {
+    set_sources_assignment_filter([])
+    action_with_pydeps(target_name) {
+      forward_variables_from(invoker,
+                             [
+                               "sources",
+                               "testonly",
+                               "visibility",
+                             ])
+
+      # The sources aren't compiled so don't check their dependencies.
+      check_includes = false
+      script = "//build/android/gyp/java_cpp_strings.py"
+
+      _srcjar_path = "${target_gen_dir}/${target_name}.srcjar"
+      _rebased_srcjar_path = rebase_path(_srcjar_path, root_build_dir)
+      _rebased_sources = rebase_path(invoker.sources, root_build_dir)
+      _rebased_template = rebase_path(invoker.template, root_build_dir)
+
+      args = [
+        "--srcjar=$_rebased_srcjar_path",
+        "--template=$_rebased_template",
+      ]
+      args += _rebased_sources
+      sources += [ invoker.template ]
+
+      outputs = [
+        _srcjar_path,
+      ]
+    }
+  }
+
   # Declare a target for processing a Jinja template.
   #
   # Variables

chrome/android/BUILD.gn

@@ -355,6 +355,7 @@ android_library("chrome_java") {
 
   srcjar_deps = [
     ":chrome_android_java_enums_srcjar",
+    ":chrome_android_java_switches_srcjar",
     ":chrome_android_java_google_api_keys_srcjar",
     ":photo_picker_aidl",
     ":resource_id_javagen",
@@ -496,6 +497,13 @@ java_cpp_enum("chrome_vr_android_java_enums_srcjar") {
   ]
 }
 
+java_cpp_strings("chrome_android_java_switches_srcjar") {
+  sources = [
+    "//chrome/common/chrome_switches.cc",
+  ]
+  template = "//chrome/android/java_templates/ChromeSwitches.java.tmpl"
+}
+
 proto_java_library("document_tab_model_info_proto_java") {
   proto_path = "java/src/org/chromium/chrome/browser/tabmodel/document"
   sources = [
@@ -718,6 +726,7 @@ android_library("chrome_test_java") {
     "//components/web_restrictions:provider_java",
     "//content/public/android:content_java",
     "//content/public/test/android:content_java_test_support",
+    "//media/base/android:java_switches",
     "//media/base/android:media_java",
     "//mojo/public/java:bindings_java",
     "//mojo/public/java:system_java",

chrome/android/java_sources.gni

@@ -37,7 +37,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/ChromeKeyboardVisibilityDelegate.java",
   "java/src/org/chromium/chrome/browser/ChromeStrictMode.java",
   "java/src/org/chromium/chrome/browser/ChromeStringConstants.java",
-  "java/src/org/chromium/chrome/browser/ChromeSwitches.java",
   "java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java",
   "java/src/org/chromium/chrome/browser/ChromeTabbedActivity2.java",
   "java/src/org/chromium/chrome/browser/ChromeVersionInfo.java",

chrome/android/java/src/org/chromium/chrome/browser/ChromeSwitches.java → chrome/android/java_templates/ChromeSwitches.java.tmpl

@@ -8,14 +8,10 @@ package org.chromium.chrome.browser;
  * Contains all of the command line switches that are specific to the chrome/
  * portion of Chromium on Android.
  */
-public abstract class ChromeSwitches {
+public abstract class ChromeSwitches {{
     // Switches used from Java.  Please continue switch style used Chrome where
     // options-have-hyphens and are_not_split_with_underscores.
 
-    /** Mimic a low end device */
-    public static final String ENABLE_ACCESSIBILITY_TAB_SWITCHER =
-            "enable-accessibility-tab-switcher";
-
     /** Whether fullscreen support is disabled (auto hiding controls, etc...). */
     public static final String DISABLE_FULLSCREEN = "disable-fullscreen";
 
@@ -68,29 +64,14 @@ public abstract class ChromeSwitches {
     public static final String DISABLE_LOFI_SNACKBAR = "disable-lo-fi-snackbar";
 
     /**
-     * Forces the update state to be set to the given state if the value is {@link
-     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#NONE_SWITCH_VALUE}, {@link
-     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#UPDATE_AVAILABLE_SWITCH_VALUE},
-     * {@link
-     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#UNSUPPORTED_OS_VERSION_SWITCH_VALUE}.
+     * Forces the update state to be set to the given state if the value is {{@link
+     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#NONE_SWITCH_VALUE}}, {{@link
+     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#UPDATE_AVAILABLE_SWITCH_VALUE}},
+     * {{@link
+     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#UNSUPPORTED_OS_VERSION_SWITCH_VALUE}}.
      */
     public static final String FORCE_UPDATE_MENU_UPDATE_TYPE = "force-update-menu-type";
 
-    /**
-     * Forces the update menu badge to show. This requires the update type to be valid as well.
-     *
-     * @see #FORCE_UPDATE_MENU_UPDATE_TYPE
-     */
-    public static final String FORCE_SHOW_UPDATE_MENU_BADGE = "force-show-update-menu-badge";
-
-    /**
-     * Sets the market URL for Chrome for use in testing. This requires setting {@link
-     * #FORCE_UPDATE_MENU_UPDATE_TYPE} to {@link
-     * org.chromium.chrome.browser.omaha.UpdateMenuItemHelper#UPDATE_AVAILABLE_SWITCH_VALUE}.
-     * @see #FORCE_UPDATE_MENU_UPDATE_TYPE
-     */
-    public static final String MARKET_URL_FOR_TESTING = "market-url-for-testing";
-
     /**
      * Disable multiwindow tab merging for testing.
      */
@@ -121,18 +102,6 @@ public abstract class ChromeSwitches {
      */
     public static final String GOOGLE_BASE_URL = "google-base-url";
 
-    /**
-     * Disable domain reliability
-     * Native switch - switches::kDisableDomainReliability
-     */
-    public static final String DISABLE_DOMAIN_RELIABILITY = "disable-domain-reliability";
-
-    /**
-     * Specifies Android phone page loading progress bar animation.
-     * Native switch - switches::kProgressBarAnimation
-     */
-    public static final String PROGRESS_BAR_ANIMATION = "progress-bar-animation";
-
     /**
      * Enables overscroll of the on screen keyboard. With this flag on, the OSK will only resize the
      * visual viewport.
@@ -229,6 +198,8 @@ public abstract class ChromeSwitches {
     public static final String DISABLE_GOOGLE_PLAY_SERVICES_FOR_TESTING =
             "disable-google-play-services-for-testing";
 
+{NATIVE_STRINGS}
+
     // Prevent instantiation.
-    private ChromeSwitches() {}
-}
+    private ChromeSwitches() {{}}
+}}

content/public/android/java/src/org/chromium/content_public/common/ContentSwitches.java → content/common/android/java_templates/ContentSwitches.java.tmpl

@@ -8,7 +8,7 @@ package org.chromium.content_public.common;
  * Contains all of the command line switches that are specific to the content/
  * portion of Chromium on Android.
  */
-public final class ContentSwitches {
+public final class ContentSwitches {{
     // Tell Java to use the official command line, loaded from the
     // official-command-line.xml files.  WARNING this is not done
     // immediately on startup, so early running Java code will not see
@@ -27,9 +27,6 @@ public final class ContentSwitches {
     // Change the url of the JavaScript that gets injected when accessibility mode is enabled.
     public static final String ACCESSIBILITY_JAVASCRIPT_URL = "accessibility-js-url";
 
-    // Sets the ISO country code that will be used for phone number detection.
-    public static final String NETWORK_COUNTRY_ISO = "network-country-iso";
-
     // How much of the browser controls need to be shown before they will auto show.
     public static final String TOP_CONTROLS_SHOW_THRESHOLD = "top-controls-show-threshold";
 
@@ -39,16 +36,9 @@ public final class ContentSwitches {
     // Native switch - chrome_switches::kDisablePopupBlocking
     public static final String DISABLE_POPUP_BLOCKING = "disable-popup-blocking";
 
-    // Native switch kDisableGestureRequirementForPresentation
-    public static final String DISABLE_GESTURE_REQUIREMENT_FOR_PRESENTATION =
-            "disable-gesture-requirement-for-presentation";
-
     // Native switch kRendererProcessLimit
     public static final String RENDER_PROCESS_LIMIT = "renderer-process-limit";
 
-    // Native switch kInProcessGPU
-    public static final String IN_PROCESS_GPU = "in-process-gpu";
-
     // Native switch kProcessType
     public static final String SWITCH_PROCESS_TYPE = "type";
 
@@ -74,6 +64,8 @@ public final class ContentSwitches {
     // Native switch value kNetworkSandbox
     public static final String NETWORK_SANDBOX_TYPE = "network";
 
+{NATIVE_STRINGS}
+
     // Prevent instantiation.
-    private ContentSwitches() {}
-}
+    private ContentSwitches() {{}}
+}}

content/public/android/BUILD.gn

@@ -93,6 +93,7 @@ android_library("content_java") {
     ":generate_sandboxed_service_srcjar",
     ":is_ready_to_pay_service_aidl",
     ":content_public_android_java_enums_srcjar",
+    ":content_public_android_java_switches_srcjar",
     "//content/browser/accessibility:content_browser_accessibility_java_enums_srcjar",
     "//ui/touch_selection:ui_touch_selection_enums_srcjar",
     "//ui/touch_selection:ui_touch_handle_orientation_srcjar",
@@ -284,7 +285,6 @@ android_library("content_java") {
     "java/src/org/chromium/content_public/browser/WebContentsObserver.java",
     "java/src/org/chromium/content_public/browser/WebContentsStatics.java",
     "java/src/org/chromium/content_public/common/ContentProcessInfo.java",
-    "java/src/org/chromium/content_public/common/ContentSwitches.java",
     "java/src/org/chromium/content_public/common/ContentUrlConstants.java",
     "java/src/org/chromium/content_public/common/Referrer.java",
     "java/src/org/chromium/content_public/common/ResourceRequestBody.java",
@@ -368,6 +368,13 @@ java_cpp_enum("content_public_android_java_enums_srcjar") {
   ]
 }
 
+java_cpp_strings("content_public_android_java_switches_srcjar") {
+  sources = [
+    "//content/public/common/content_switches.cc",
+  ]
+  template = "//content/common/android/java_templates/ContentSwitches.java.tmpl"
+}
+
 generate_jar_jni("jar_jni") {
   jni_package = "content"
   classes = [

docs/android_accessing_cpp_switches_in_java.md

+# Accessing C++ Switches In Java
+
+[TOC]
+
+## Introduction
+
+Accessing C++ switches in Java is implemented via a Python script which analyzes
+the C++ switches file and spits out the corresponding Java class. The generated
+class name will be based upon the switch file name, and the path must be
+specified in a comment within the switch file itself.
+
+## Usage
+
+1. Add directives to your C++ switch file
+
+    ```cpp
+    // GENERATED_JAVA_PACKAGE: org.chromium.chrome
+
+    // ...snip...
+
+    // Documentation for the following switch.
+    const char kSomeSwitch[] = "some-switch";
+
+    // ...snip...
+    ```
+
+2. Create a template file
+   ```java
+    // Copyright {YEAR} 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.
+
+    // This file is autogenerated by
+    //     {SCRIPT_NAME}
+    // From
+    //     {SOURCE_PATH}, and
+    //     {TEMPLATE_PATH}
+
+    package my.java.package
+
+    // Be sure to escape any curly braces in your template by doubling as
+    // follows.
+    public abstract class MySwitches {{
+
+    {NATIVE_SWITCHES}
+
+    }}
+   ```
+
+3. Add a new build target
+
+    ```gn
+    import("//build/config/android/rules.gni")
+
+    java_cpp_strings("foo_generated_switch") {
+      sources = [
+        "//base/android/native_foo_switches.cc",
+      ]
+      template = "//base/android/java_templates/MySwitches.java.tmpl"
+    }
+    ```
+
+5. Add the new target to the desired android_library targets srcjar_deps:
+
+    ```gn
+    android_library("base_java") {
+      srcjar_deps = [
+        ":foo_generated_switches",
+      ]
+    }
+    ```
+
+5. The generated file `org/chromium/chrome/NativeFooSwitches.java` would contain:
+
+    ```java
+    package org.chromium.chrome;
+
+    public final class NativeFooSwitches {
+        // ...snip...
+
+        public static final String SOME_SWITCH = "some-switch";
+
+        // ...snip...
+    }
+    ```
+
+## Code
+* [Generator
+code](https://cs.chromium.org/chromium/src/build/android/gyp/java_cpp_strings.py?dr=C&sq=package:chromium)
+and
+[Tests](https://cs.chromium.org/chromium/src/build/android/gyp/java_cpp_strings_tests.py?dr=C&sq=package:chromium)
+* [GN
+template](https://cs.chromium.org/chromium/src/build/config/android/rules.gni?sq=package:chromium&dr=C)

media/base/android/BUILD.gn

@@ -154,6 +154,13 @@ if (is_android) {
     ]
   }
 
+  java_cpp_strings("java_switches") {
+    sources = [
+      "//media/base/media_switches.cc",
+    ]
+    template = "//media/base/android/java_templates/MediaSwitches.java.tmpl"
+  }
+
   android_resources("media_java_resources") {
     custom_package = "org.chromium.media"
     resource_dirs = [ "java/res" ]
@@ -167,6 +174,7 @@ if (is_android) {
     ]
     srcjar_deps = [
       ":java_enums",
+      ":java_switches",
       "//media/base:java_enums",
     ]
     java_files = [
@@ -187,7 +195,6 @@ if (is_android) {
       "java/src/org/chromium/media/MediaPlayerBridge.java",
       "java/src/org/chromium/media/MediaPlayerListener.java",
       "java/src/org/chromium/media/MediaServerCrashListener.java",
-      "java/src/org/chromium/media/MediaSwitches.java",
     ]
   }
 

media/base/android/java/src/org/chromium/media/MediaSwitches.java → media/base/android/java_templates/MediaSwitches.java.tmpl

@@ -7,7 +7,7 @@ package org.chromium.media;
 /**
  * Contains command line switches that are specific to the media layer.
  */
-public abstract class MediaSwitches {
+public abstract class MediaSwitches {{
     // Set the autoplay policy to ignore user gesture requirements
     public static final String AUTOPLAY_NO_GESTURE_REQUIRED_POLICY =
             "autoplay-policy=no-user-gesture-required";
@@ -15,6 +15,8 @@ public abstract class MediaSwitches {
     // TODO(819383): Remove this and its usage.
     public static final String USE_MODERN_MEDIA_CONTROLS = "UseModernMediaControls";
 
+{NATIVE_STRINGS}
+
     // Prevents instantiation.
-    private MediaSwitches() {}
-}
+    private MediaSwitches() {{}}
+}}