Harmonize SpdyFrameType enum values with wire values.

Also change ParseFrameType() return value for invalid frame types.  This
does not matter in SpdyFramer::ValidateFrameHeader(), because the call
to ParseFrameType() is preceeded by a call to IsValidFrameType().

This CL lands server change 143677028 by bnc.

BUG=488484

Review-Url: https://codereview.chromium.org/2619493005
Cr-Commit-Position: refs/heads/master@{#442903}

net/spdy/spdy_protocol.cc

@@ -46,54 +46,13 @@ SpdyPriority Http2WeightToSpdy3Priority(int weight) {
 }
 
 bool IsValidFrameType(int frame_type_field) {
-  // Check for recognized extensions.
-  if (frame_type_field == SerializeFrameType(ALTSVC) ||
-      frame_type_field == SerializeFrameType(BLOCKED)) {
-    return true;
-  }
-
-  // DATA is the first valid frame.
-  if (frame_type_field < SerializeFrameType(DATA)) {
-    return false;
-  }
-
-  // CONTINUATION is the last valid frame.
-  if (frame_type_field > SerializeFrameType(CONTINUATION)) {
-    return false;
-  }
-
-  return true;
+  return frame_type_field >= MIN_FRAME_TYPE &&
+         frame_type_field <= MAX_FRAME_TYPE;
 }
 
 SpdyFrameType ParseFrameType(int frame_type_field) {
-  switch (frame_type_field) {
-    case 0:
-      return DATA;
-    case 1:
-      return HEADERS;
-    case 2:
-      return PRIORITY;
-    case 3:
-      return RST_STREAM;
-    case 4:
-      return SETTINGS;
-    case 5:
-      return PUSH_PROMISE;
-    case 6:
-      return PING;
-    case 7:
-      return GOAWAY;
-    case 8:
-      return WINDOW_UPDATE;
-    case 9:
-      return CONTINUATION;
-    case 10:
-      return ALTSVC;
-    case 11:
-      return BLOCKED;
-  }
-  SPDY_BUG << "Unhandled frame type " << frame_type_field;
-  return DATA;
+  SPDY_BUG_IF(!IsValidFrameType(frame_type_field)) << "Invalid frame type.";
+  return static_cast<SpdyFrameType>(frame_type_field);
 }
 
 int SerializeFrameType(SpdyFrameType frame_type) {

net/spdy/spdy_protocol.h

@@ -74,19 +74,21 @@ const int kHttp2ConnectionHeaderPrefixSize =
 
 // Types of HTTP2 frames.
 enum SpdyFrameType {
-  DATA,
-  RST_STREAM,
-  SETTINGS,
-  PING,
-  GOAWAY,
-  HEADERS,
-  WINDOW_UPDATE,
-  PUSH_PROMISE,
-  CONTINUATION,
-  PRIORITY,
-  // BLOCKED and ALTSVC are recognized extensions.
-  BLOCKED,
-  ALTSVC,
+  DATA = 0x00,
+  MIN_FRAME_TYPE = DATA,
+  HEADERS = 0x01,
+  PRIORITY = 0x02,
+  RST_STREAM = 0x03,
+  SETTINGS = 0x04,
+  PUSH_PROMISE = 0x05,
+  PING = 0x06,
+  GOAWAY = 0x07,
+  WINDOW_UPDATE = 0x08,
+  CONTINUATION = 0x09,
+  // ALTSVC and BLOCKED are recognized extensions.
+  ALTSVC = 0x0a,
+  BLOCKED = 0x0b,
+  MAX_FRAME_TYPE = BLOCKED
 };
 
 // Flags on data packets.