Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/source_span/lib/src/span_mixin.dart

Index: mojo/public/dart/third_party/source_span/lib/src/span_mixin.dart
diff --git a/mojo/public/dart/third_party/source_span/lib/src/span_mixin.dart b/mojo/public/dart/third_party/source_span/lib/src/span_mixin.dart
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+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library source_span.span_mixin;
+
+import 'dart:math' as math;
+import 'package:path/path.dart' as p;
+
+import 'colors.dart' as colors;
+import 'span.dart';
+import 'span_with_context.dart';
+import 'utils.dart';
+
+/// A mixin for easily implementing [SourceSpan].
+///
+/// This implements the [SourceSpan] methods in terms of [start], [end], and
+/// [text]. This assumes that [start] and [end] have the same source URL, that
+/// [start] comes before [end], and that [text] has a number of characters equal
+/// to the distance between [start] and [end].
+abstract class SourceSpanMixin implements SourceSpan {
+  Uri get sourceUrl => start.sourceUrl;
+  int get length => end.offset - start.offset;
+
+  int compareTo(SourceSpan other) {
+    var result = start.compareTo(other.start);
+    return result == 0 ? end.compareTo(other.end) : result;
+  }
+
+  SourceSpan union(SourceSpan other) {
+    if (sourceUrl != other.sourceUrl) {
+      throw new ArgumentError("Source URLs \"${sourceUrl}\" and "
+          " \"${other.sourceUrl}\" don't match.");
+    }
+
+    var start = min(this.start, other.start);
+    var end = max(this.end, other.end);
+    var beginSpan = start == this.start ? this : other;
+    var endSpan = end == this.end ? this : other;
+
+    if (beginSpan.end.compareTo(endSpan.start) < 0) {
+      throw new ArgumentError("Spans $this and $other are disjoint.");
+    }
+
+    var text = beginSpan.text +
+        endSpan.text.substring(beginSpan.end.distance(endSpan.start));
+    return new SourceSpan(start, end, text);
+  }
+
+  String message(String message, {color}) {
+    if (color == true) color = colors.RED;
+    if (color == false) color = null;
+
+    var line = start.line;
+    var column = start.column;
+
+    var buffer = new StringBuffer();
+    buffer.write('line ${line + 1}, column ${column + 1}');
+    if (sourceUrl != null) buffer.write(' of ${p.prettyUri(sourceUrl)}');
+    buffer.write(': $message');
+
+    if (length == 0 && this is! SourceSpanWithContext) return buffer.toString();
+    buffer.write("\n");
+
+    var textLine;
+    if (this is SourceSpanWithContext) {
+      var context = (this as SourceSpanWithContext).context;
+      var lineStart = findLineStart(context, text, column);
+      if (lineStart != null && lineStart > 0) {
+        buffer.write(context.substring(0, lineStart));
+        context = context.substring(lineStart);
+      }
+      var endIndex = context.indexOf('\n');
+      textLine = endIndex == -1 ? context : context.substring(0, endIndex + 1);
+      column = math.min(column, textLine.length - 1);
+    } else {
+      textLine = text.split("\n").first;
+      column = 0;
+    }
+
+    var toColumn =
+        math.min(column + end.offset - start.offset, textLine.length);
+    if (color != null) {
+      buffer.write(textLine.substring(0, column));
+      buffer.write(color);
+      buffer.write(textLine.substring(column, toColumn));
+      buffer.write(colors.NONE);
+      buffer.write(textLine.substring(toColumn));
+    } else {
+      buffer.write(textLine);
+    }
+    if (!textLine.endsWith('\n')) buffer.write('\n');
+    buffer.write(' ' * column);
+    if (color != null) buffer.write(color);
+    buffer.write('^' * math.max(toColumn - column, 1));
+    if (color != null) buffer.write(colors.NONE);
+    return buffer.toString();
+  }
+
+  bool operator ==(other) => other is SourceSpan &&
+      start == other.start && end == other.end;
+
+  int get hashCode => start.hashCode + (31 * end.hashCode);
+
+  String toString() => '<$runtimeType: from $start to $end "$text">';
+}