test-results: package model: Add full_result.go and tests

go/src/infra/appengine/test-results/model/common.go

 package model
 
 import (
         "bytes"
-        "math"
         "strconv"
 )
 
-func round(f float64) int {
-        if math.Abs(f) < 0.5 {
-                return 0
-        }
-        return int(f + math.Copysign(0.5, f))
+// Node is a node in a Tests tree.
+//
+// In reality, it as almost as weak as empty interface,
+// but the unexported method allow the package to achieve
+// type safety internally.
+type Node interface {
+        node()
 }
 
-// TestNode is a node in a Tests tree.
-type TestNode interface {
-        // Children returns a map of a TestNode's children.
-        Children() map[string]TestNode
+// Number is an integer that supports JSON unmarshaling from a string
+// and marshaling back to a string.
+type Number int
 
-        testnode()
-}
-
-// number is an integer that supports JSON unmarshaling from a string
-// and marshaling back to a string.
-type number int
-
-func (n *number) UnmarshalJSON(data []byte) error {
+// UnmarshalJSON unmarshals data into n.
+// data is expected to be a JSON string. If the string
+// fails to parse to an integer, UnmarshalJSON returns
+// an error.
+func (n *Number) UnmarshalJSON(data []byte) error {
         data = bytes.Trim(data, `"`)
         num, err := strconv.Atoi(string(data))
         if err != nil {
                 return err
         }
-        *n = number(num)
+        *n = Number(num)
         return nil
 }
 
-func (n *number) MarshalJSON() ([]byte, error) {
+// MarshalJSON marshals n into JSON string.
+func (n *Number) MarshalJSON() ([]byte, error) {
         return []byte(strconv.Itoa(int(*n))), nil
 }