Add UMA for measuring Content-Dispostion header use and abuse.

net/http/http_content_disposition.h

Index: net/http/http_content_disposition.h
diff --git a/net/http/http_content_disposition.h b/net/http/http_content_disposition.h
index f3573a9dceadcc27a6c9c54e8b7c0452b4f3e2a4..2b4ca709eb3cbb581bab6c9101eda889fc0a3141 100644
--- a/net/http/http_content_disposition.h
+++ b/net/http/http_content_disposition.h
@@ -19,6 +19,37 @@ class NET_EXPORT HttpContentDisposition {
     ATTACHMENT,
   };
 
+  // Properties of the Content-Disposition header. Used for UMA.
+  enum ParseResultFlags {
+    INVALID                      = 0,
+
+    // A valid disposition-type is present.
+    HAS_DISPOSITION_TYPE         = 1 << 0,
+
+    // The disposition-type is not 'inline' or 'attachment'.
+    HAS_UNKNOWN_DISPOSITION_TYPE = 1 << 1,
+
+    // Has a valid non-empty 'name' attribute.
+    HAS_NAME                     = 1 << 2,
+
+    // Has a valid non-empty 'filename' attribute.
+    HAS_FILENAME                 = 1 << 3,
+
+    // Has a valid non-empty 'filename*' attribute.
+    HAS_EXT_FILENAME             = 1 << 4,
+
+    // The following fields are properties of the 'filename' attribute:
+
+    // Quoted-string contains non-ASCII characters.
+    HAS_NON_ASCII_STRINGS        = 1 << 5,
+
+    // Quoted-string contains percent-encoding.
+    HAS_PERCENT_ENCODED_STRINGS  = 1 << 6,
+
+    // Quoted-string contains RFC 2047 encoded words.
+    HAS_RFC2047_ENCODED_STRINGS  = 1 << 7
+  };
+
   HttpContentDisposition(const std::string& header,
                          const std::string& referrer_charset);
   ~HttpContentDisposition();
@@ -28,6 +59,9 @@ class NET_EXPORT HttpContentDisposition {
   Type type() const { return type_; }
   const std::string& filename() const { return filename_; }
 
+  // A combination of ParseResultFlags values.
+  int parse_result_flags() const { return parse_result_flags_; }
+
  private:
   void Parse(const std::string& header, const std::string& referrer_charset);
   std::string::const_iterator ConsumeDispositionType(
@@ -35,6 +69,7 @@ class NET_EXPORT HttpContentDisposition {
 
   Type type_;
   std::string filename_;
+  int parse_result_flags_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpContentDisposition);
 };