Roll Observatory packages and add a roll script

packages/dart_style/test/whitespace/if.stmt

Index: packages/dart_style/test/whitespace/if.stmt
diff --git a/packages/dart_style/test/whitespace/if.stmt b/packages/dart_style/test/whitespace/if.stmt
new file mode 100644
index 0000000000000000000000000000000000000000..0403400b9666d9cad53bb4ada179500c68cdd3b9
--- /dev/null
+++ b/packages/dart_style/test/whitespace/if.stmt
@@ -0,0 +1,64 @@
+40 columns                              |
+>>> indentation
+if(true){return 42;}else{return 13;}
+<<<
+if (true) {
+  return 42;
+} else {
+  return 13;
+}
+>>> nested
+if (true){
+if (true){
+if (true){
+return true;
+} else{
+return false;
+}
+}
+}else{
+return false;
+}
+<<<
+if (true) {
+  if (true) {
+    if (true) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+} else {
+  return false;
+}
+>>> single-expression then body
+if(true)print("true!");
+<<<
+if (true) print("true!");
+>>> block then body
+if(true){print("true!");}
+<<<
+if (true) {
+  print("true!");
+}
+>>> single-expression else body
+if(true)print(1);else print(0);
+<<<
+if (true) print(1);
+else print(0);
+>>> chained else if
+if (0 == 0) {
+  zero = 0;
+} else if (0 == 1) {
+  zero = 1;
+} else if (0 == 2) {
+  zero = 2;
+}
+<<<
+if (0 == 0) {
+  zero = 0;
+} else if (0 == 1) {
+  zero = 1;
+} else if (0 == 2) {
+  zero = 2;
+}