refactor(dart): Format Dart code

Use the dart formatter to clean up all pure Dart code.

Closes #4832

modules/angular2/src/core/dom/abstract_html_adapter.dart

@@ -340,13 +340,13 @@ abstract class AbstractHtml5LibAdapter implements DomAdapter {
     throw 'not implemented';
   }
 
-  bool isPageRule(rule)  => (rule.type == 6);
+  bool isPageRule(rule) => (rule.type == 6);
 
   bool isStyleRule(rule) => (rule.type == 1);
 
   bool isMediaRule(rule) => (rule.type == 4);
 
-  bool isKeyframesRule(rule)  => (rule.type == 7);
+  bool isKeyframesRule(rule) => (rule.type == 7);
 
   String getHref(element) {
     throw 'not implemented';

modules/angular2/src/core/dom/browser_adapter.dart

@@ -98,7 +98,7 @@ final _keyCodeToKeyMap = const {
 final bool _supportsTemplateElement = () {
   try {
     return new TemplateElement().content != null;
-  } catch(_) {
+  } catch (_) {
     return false;
   }
 }();
@@ -216,7 +216,8 @@ class BrowserDomAdapter extends GenericBrowserDomAdapter {
   String nodeName(Node el) => el.nodeName;
   String nodeValue(Node el) => el.nodeValue;
   String type(InputElement el) => el.type;
-  Node content(TemplateElement el) => _supportsTemplateElement ? el.content : el;
+  Node content(TemplateElement el) =>
+      _supportsTemplateElement ? el.content : el;
   Node firstChild(el) => el.firstChild;
   Node nextSibling(Node el) => el.nextNode;
   Element parentElement(Node el) => el.parent;
@@ -456,7 +457,7 @@ class BrowserDomAdapter extends GenericBrowserDomAdapter {
   setGlobalVar(String path, value) {
     var parts = path.split('.');
     var obj = js.context;
-    while(parts.length > 1) {
+    while (parts.length > 1) {
       var name = parts.removeAt(0);
       if (obj.hasProperty(name)) {
         obj = obj[name];

modules/angular2/src/core/dom/emulated_css.dart

@@ -18,22 +18,19 @@ List<EmulatedCssRule> parseAndEmulateCssRules(String css) {
 
 /// Converts `csslib` [rules] to their emulated counterparts.
 List<EmulatedCssRule> emulateRules(Iterable<cssv.TreeNode> rules) {
-  return rules
-    .map((cssv.TreeNode node) {
-      if (node is cssv.RuleSet) {
-        if (node.declarationGroup.span.text.isEmpty) {
-          // Skip CSS matchers with no bodies
-          return null;
-        }
-        return new EmulatedCssStyleRule(node);
-      } else if (node is cssv.MediaDirective) {
-        return new EmulatedCssMedialRule(node);
-      } else if (node is cssv.ImportDirective) {
-        return new EmulatedCssImportRule(node);
+  return rules.map((cssv.TreeNode node) {
+    if (node is cssv.RuleSet) {
+      if (node.declarationGroup.span.text.isEmpty) {
+        // Skip CSS matchers with no bodies
+        return null;
       }
-    })
-    .where((r) => r != null)
-    .toList();
+      return new EmulatedCssStyleRule(node);
+    } else if (node is cssv.MediaDirective) {
+      return new EmulatedCssMedialRule(node);
+    } else if (node is cssv.ImportDirective) {
+      return new EmulatedCssImportRule(node);
+    }
+  }).where((r) => r != null).toList();
 }
 
 /// Emulates [CSSRule](https://developer.mozilla.org/en-US/docs/Web/API/CSSRule)
@@ -98,8 +95,8 @@ class EmulatedMediaList {
   String mediaText;
 
   EmulatedMediaList(cssv.MediaDirective directive) {
-    this.mediaText = directive.mediaQueries
-        .map((q) => q.span.text).join(' and ');
+    this.mediaText =
+        directive.mediaQueries.map((q) => q.span.text).join(' and ');
   }
 }