minor usage and readme fixes

[email protected]

Review URL: https://codereview.chromium.org/1451043002 .

Author: John Messerly

pkg/dev_compiler/README.md

@@ -26,6 +26,6 @@ DDC has the following project goals:
 DDC is still in a very early stage as highlighted by our choice of ES6.  ES6 itself is in active development across all modern browsers, but at various stages of support:
 [kangax.github.io/compat-table/es6](https://kangax.github.io/compat-table/es6/).
 
-We are initially targeting the subset of ES6 supported in Chrome Canary.
+We are targeting the subset of ES6 supported in Chrome.
 
 To try out DDC and/or give feedback, please read our [usage](https://github.com/dart-lang/dev_compiler/blob/master/USAGE.md) page.

pkg/dev_compiler/USAGE.md

@@ -32,9 +32,10 @@ void main() {
 ```
 
 the Dart analyzer will not report a static error or warning even
-though the program will clearly fail (in checked mode).  Running DDC:
+though the program will clearly fail (in checked mode).  Running with --strong
+mode:
 
-    $ dartdevc main.dart
+    $ dartanalyzer --strong main.dart
 
 will display a severe error.  Modifying `42` to `'42'` will
 correct the error.