Add metrics for schemes of content setting exceptions

components/content_settings/core/common/content_settings_pattern.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/content_settings/core/common/content_settings_pattern.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "components/content_settings/core/common/content_settings_pattern_parser.h"
 #include "net/base/url_util.h"
 #include "url/gurl.h"
 
 namespace {
 
 // The component supports only one scheme for simplicity.
 const char* non_port_non_domain_wildcard_scheme = NULL;
 
+const char* const kSchemeNames[] = {
+  "wildcard",
+  url::kHttpScheme,
+  url::kHttpsScheme,
+  url::kFileScheme,
+  "chrome-extension",
+  "other",
+};
+
 std::string GetDefaultPort(const std::string& scheme) {
   if (scheme == url::kHttpScheme)
     return "80";
   if (scheme == url::kHttpsScheme)
     return "443";
   return std::string();
 }
 
 // Returns true if |sub_domain| is a sub domain or equals |domain|.  E.g.
 // "mail.google.com" is a sub domain of "google.com" but "evilhost.com" is not a
@@ skipping 549 matching lines @@
   return parts_.has_domain_wildcard && parts_.host.empty();
 }
 
 std::string ContentSettingsPattern::ToString() const {
   if (IsValid())
     return content_settings::PatternParser::ToString(parts_);
   else
     return std::string();
 }
 
+ContentSettingsPattern::SchemeType ContentSettingsPattern::GetScheme() const {
+  if (parts_.is_scheme_wildcard)
+    return SCHEME_WILDCARD;
+
+  for (int i = 1; i < SCHEME_MAX - 1; ++i) {

[msramek, 2016/08/09 10:47:43]

We're iterating over kSchemeNames, so I would specify arraysize(kSchemeNames) as
the top bound. There currently isn't any coupling between kSchemeNames and
SCHEME_MAX, i.e. it can't be easily verified that this loop won't go out of
bounds.

Please also introduce such a coupling by adding
static_assert(arraysize(kSchemeNames) == SCHEME_MAX - 1)

[lshang, 2016/08/10 04:32:35]

Done. Good advice!

+    if (parts_.scheme == kSchemeNames[i]) {

[msramek, 2016/08/09 10:47:43]

nit: No braces needed for a one-line for() :)

[lshang, 2016/08/10 04:32:35]

Done.

+      return static_cast<SchemeType>(i);
+    }
+  }
+  return SCHEME_OTHER;
+}
+
 ContentSettingsPattern::Relation ContentSettingsPattern::Compare(
     const ContentSettingsPattern& other) const {
   // Two invalid patterns are identical in the way they behave. They don't match
   // anything and are represented as an empty string. So it's fair to treat them
   // as identical.
   if ((this == &other) ||
       (!is_valid_ && !other.is_valid_))
     return IDENTITY;
 
   if (!is_valid_ && other.is_valid_)
@@ skipping 188 matching lines @@
   if (!parts.is_path_wildcard && other_parts.is_path_wildcard)
     return ContentSettingsPattern::PREDECESSOR;
 
   int result = parts.path.compare(other_parts.path);
   if (result == 0)
     return ContentSettingsPattern::IDENTITY;
   if (result > 0)
     return ContentSettingsPattern::DISJOINT_ORDER_PRE;
   return ContentSettingsPattern::DISJOINT_ORDER_POST;
 }