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

mojo/public/dart/third_party/source_span/CHANGELOG.md

+# 1.2.0
+
+* **Deprecated:** Extending `SourceLocation` directly is deprecated. Instead,
+  extend the new `SourceLocationBase` class or mix in the new
+  `SourceLocationMixin` mixin.
+
+* Dramatically improve the performance of `FileLocation`.
+
+# 1.1.6
+
+* Optimize `getLine()` in `SourceFile` when repeatedly called.
+
+# 1.1.5
+
+* Fixed another case in which `FileSpan.union` could throw an exception for
+  external implementations of `FileSpan`.
+
+# 1.1.4
+
+* Eliminated dart2js warning about overriding `==`, but not `hashCode`.
+
+# 1.1.3
+
+* `FileSpan.compareTo`, `FileSpan.==`, `FileSpan.union`, and `FileSpan.expand`
+  no longer throw exceptions for external implementations of `FileSpan`.
+
+* `FileSpan.hashCode` now fully agrees with `FileSpan.==`.
+
+# 1.1.2
+
+* Fixed validation in `SourceSpanWithContext` to allow multiple occurrences of
+  `text` within `context`.
+
+# 1.1.1
+
+* Fixed `FileSpan`'s context to include the full span text, not just the first
+  line of it.
+
+# 1.1.0
+
+* Added `SourceSpanWithContext`: a span that also includes the full line of text
+  that contains the span.
+
+# 1.0.3
+
+* Cleanup equality operator to accept any Object rather than just a
+  `SourceLocation`.
+
+# 1.0.2
+
+* Avoid unintentionally allocating extra objects for internal `FileSpan`
+  operations.
+
+* Ensure that `SourceSpan.operator==` works on arbitrary `Object`s.
+
+# 1.0.1
+
+* Use a more compact internal representation for `FileSpan`.
+
+# 1.0.0
+
+This package was extracted from the
+[`source_maps`](http://pub.dartlang.org/packages/source_maps) package, but the
+API has many differences. Among them:
+
+* `Span` has been renamed to `SourceSpan` and `Location` has been renamed to
+  `SourceLocation` to clarify their purpose and maintain consistency with the
+  package name. Likewise, `SpanException` is now `SourceSpanException` and
+  `SpanFormatException` is not `SourceSpanFormatException`.
+
+* `FixedSpan` and `FixedLocation` have been rolled into the `Span` and
+  `Location` classes, respectively.
+
+* `SourceFile` is more aggressive about validating its arguments. Out-of-bounds
+  lines, columns, and offsets will now throw errors rather than be silently
+  clamped.
+
+* `SourceSpan.sourceUrl`, `SourceLocation.sourceUrl`, and `SourceFile.url` now
+  return `Uri` objects rather than `String`s. The constructors allow either
+  `String`s or `Uri`s.
+
+* `Span.getLocationMessage` and `SourceFile.getLocationMessage` are now
+  `SourceSpan.message` and `SourceFile.message`, respectively. Rather than
+  taking both a `useColor` and a `color` parameter, they now take a single
+  `color` parameter that controls both whether and which color is used.
+
+* `Span.isIdentifier` has been removed. This property doesn't make sense outside
+  of a source map context.
+
+* `SourceFileSegment` has been removed. This class wasn't widely used and was
+  inconsistent in its choice of which parameters were considered relative and
+  which absolute.