Roll Observatory packages and add a roll script

packages/dart_style/test/splitting/constructors.unit

Index: packages/dart_style/test/splitting/constructors.unit
diff --git a/packages/dart_style/test/splitting/constructors.unit b/packages/dart_style/test/splitting/constructors.unit
new file mode 100644
index 0000000000000000000000000000000000000000..4758102d68f380480b7c0318a0d770d94c757279
--- /dev/null
+++ b/packages/dart_style/test/splitting/constructors.unit
@@ -0,0 +1,84 @@
+40 columns                              |
+>>> Single initializers can be on one line
+class Foo extends Bar {
+  final int b;
+  Foo(int a, this.b) : super(a);
+}
+<<<
+class Foo extends Bar {
+  final int b;
+  Foo(int a, this.b) : super(a);
+}
+>>> (or not)
+class Foo extends Bar {
+  final int b;
+  Foo(int a, this.b): super(aLongIdentifier);
+}
+<<<
+class Foo extends Bar {
+  final int b;
+  Foo(int a, this.b)
+      : super(aLongIdentifier);
+}
+>>> Multiple initializers are one per line
+class Foo extends Bar {
+  final int b;
+  Foo(int a, int b) : super(a), this.b = b == null ? 0 : b;
+}
+<<<
+class Foo extends Bar {
+  final int b;
+  Foo(int a, int b)
+      : super(a),
+        this.b = b == null ? 0 : b;
+}
+>>> try to keep constructor call together
+var longIdentifier = new Thing(
+    argument, argument);
+<<<
+var longIdentifier =
+    new Thing(argument, argument);
+>>> splits before ":" if the parameter list does not fit on one line
+class Foo {
+  Foo(int longArg1, int longArg2, int longArg3) : this._(longArg1);
+}
+<<<
+class Foo {
+  Foo(int longArg1, int longArg2,
+      int longArg3)
+      : this._(longArg1);
+}
+>>> indent parameters more if body is a wrapped =>
+class Foo {
+  Foo(firstArgument, secondArgument, third) => "very long body that must wrap";
+}
+<<<
+class Foo {
+  Foo(firstArgument, secondArgument,
+          third) =>
+      "very long body that must wrap";
+}
+>>> wrap initializers past the ":"
+class Foo {
+  Foo(parameter)
+      : initializer = function(argument, argument),
+        initializer2 = function(argument, argument);
+}
+<<<
+class Foo {
+  Foo(parameter)
+      : initializer = function(
+            argument, argument),
+        initializer2 = function(
+            argument, argument);
+}
+>>> split at "=" in initializer
+class Foo {
+  Foo() : initializer =function(argument, arg);
+}
+<<<
+class Foo {
+  Foo()
+      : initializer =
+            function(argument, arg);
+}