Update kernel/binary.md.

pkg/kernel/binary.md

Index: pkg/kernel/binary.md
diff --git a/pkg/kernel/binary.md b/pkg/kernel/binary.md
index 6f8a03aecd2850df25778ecfc7cb1b537c5da597..71b7f33be578d2f26c9a19dd6dc08a236b440055 100644
--- a/pkg/kernel/binary.md
+++ b/pkg/kernel/binary.md
@@ -42,45 +42,43 @@ type UInt30 extends UInt {
 
 type MagicWord = big endian 32-bit unsigned integer
 
+type List<T> {
+  UInt length;
+  T[length] items;
+}
+
 type String {
-  UInt num_bytes;
-  Byte[num_bytes] utf8_bytes;
+  List<Byte> utf8Bytes;
 }
 
 type StringTable {
-  UInt num_strings;
-  String[num_strings] strings;
+  List<String> strings;
 }
 
 type StringReference {
-  UInt index; // Index into the StringTable.
+  UInt index; // Index into the StringTable strings.
 }
 
 type LineStarts {
-  UInt lineCount;
-  // Delta encoded, e.g. 0, 10, 15, 7, 10 means 0, 10, 25, 32, 42.
-  UInt[lineCount] lineStarts;
+  // Line starts are delta-encoded (they are encoded as line lengths).  The list
+  // [0, 10, 25, 32, 42] is encoded as [0, 10, 15, 7, 10].
+  List<Uint> lineStarts;
 }
 
 type UriLineStarts {
-  StringTable uris;
-  LineStarts[uris.num_strings] lineStarts;
+  List<String> uris;
+  LineStarts[uris.length] lineStarts;
 }
 
 type UriReference {
-  UInt index; // Index into the URIs StringTable.
+  UInt index; // Index into the UriLineStarts uris.
 }
 
 type FileOffset {
-  // Saved as number+1 to accommodate literal "-1".
+  // Encoded as offset + 1 to accommodate -1 indicating no offset.
   UInt fileOffset;
 }
 
-type List<T> {
-  UInt length;
-  T[length] items;
-}
-
 type Option<T> {
   Byte tag;
 }
@@ -96,13 +94,12 @@ type ProgramFile {
   MagicWord magic = 0x90ABCDEF;
   StringTable strings;
   UriLineStarts lineStartsMap;
-  List<Library> library;
+  List<Library> libraries;
   LibraryProcedureReference mainMethod;
 }
 
 type LibraryReference {
-  // For library files, this is an index into the import table.
-  // For program files, this is an index into the list of libaries.
+  // Index into the ProgramFile libraries.
   UInt index;
 }
 
@@ -169,8 +166,11 @@ type Name {
 type Library {
   Byte flags (isExternal);
   StringReference name;
-  // A URI with the dart, package, or file scheme.  For file URIs, the path
-  // is an absolute path to the .dart file from which the library was created.
+  // A URI from which the library was created.  The URI has the dart, package,
+  // file, or app scheme.  For file URIs, the path is an absolute path to the
+  // .dart file from which the library was created.  For app URIs, the path is
+  // relative to an application root that was specified when the binary was
+  // generated.
   StringReference importUri;
   // An absolute path URI to the .dart file from which the library was created.
   UriReference fileUri;