Add net/spdy/PRESUBMIT.py.

Add net/spdy/PRESUBMIT.py that checks files in net/spdy/core and
net/spdy/platform/api to make sure that classes, functions, and macros
that have been factored out into net/spdy/platform are only used in that
form in shared code.

Review-Url: https://codereview.chromium.org/2847613002
Cr-Commit-Position: refs/heads/master@{#467969}

net/spdy/PRESUBMIT.py

+# Copyright 2017 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 re
+
+def CheckForbiddenRegex(change, forbidden_regex, message_type, message):
+  problems = []
+  for path, change_per_file in change:
+    line_num = 1
+    for line in change_per_file:
+      if forbidden_regex.match(line):
+        problems.extend(["  %s:%d" % (path, line_num)])
+      line_num += 1
+  if not problems:
+    return []
+  return [message_type(message + ":\n" + "\n".join(problems))]
+
+
+def CheckChange(input_api, message_type):
+  result = []
+  shared_source_files = re.compile("^net/spdy/(core|platform/api)/.*\.(h|cc)$")
+  change = [(affected_file.LocalPath(), affected_file.NewContents())
+            for affected_file in input_api.AffectedTestableFiles()
+            if shared_source_files.match(affected_file.LocalPath())]
+  forbidden_regex_list = [
+      r"^#include \"net/base/net_export.h\"$",
+      r"\bNET_EXPORT\b",
+      r"\bNET_EXPORT_PRIVATE\b",
+      "^#include <string>$",
+      r"\bstd::string\b",
+      r"^#include \"base/strings/string_piece.h\"$",
+      r"\bbase::StringPiece\b",
+      r"\bbase::StringPrintf\b",
+      r"\bbase::StringAppendF\b",
+      r"\bbase::HexDigitToInt\b",
+  ]
+  messages = [
+      "Include \"spdy/platform/api/spdy_export.h\" "
+          "instead of \"net/base/net_export.h\"",
+      "Use SPDY_EXPORT instead of NET_EXPORT",
+      "Use SPDY_EXPORT_PRIVATE instead of NET_EXPORT_PRIVATE",
+      "Include \"spdy/platform/api/spdy_string.h\" instead of <string>",
+      "Use SpdyString instead of std::string",
+      "Include \"spdy/platform/api/spdy_string_piece.h\" "
+          "instead of \"base/strings/string_piece.h\"",
+      "Use SpdyStringPiece instead of base::StringPiece",
+      "Use SpdyStringPrintf instead of base::StringPrintf",
+      "Use SpdyStringAppendF instead of base::StringAppendF",
+      "Use SpdyHexDigitToInt instead of base::HexDigitToInt",
+  ]
+  for forbidden_regex, message in zip(forbidden_regex_list, messages):
+    result.extend(CheckForbiddenRegex(
+        change, re.compile(forbidden_regex), message_type, message))
+  return result
+
+# Warn before uploading but allow developer to skip warning
+# so that CLs can be shared and reviewed before addressing all issues.
+def CheckChangeOnUpload(input_api, output_api):
+  return CheckChange(input_api, output_api.PresubmitPromptWarning)
+
+# Do not allow code with forbidden patterns to be checked in.
+def CheckChangeOnCommit(input_api, output_api):
+  return CheckChange(input_api, output_api.PresubmitError)