Move style guide to website.

CONTRIBUTING.md

@@ -106,9 +106,11 @@ To start working on a patch:
 
  * `git fetch upstream`
  * `git checkout upstream/master -b name_of_your_branch`
- * Hack away. Please peruse our [style guides](sky/specs/style-guide.md) and [design
-   principles](sky/specs/design.md) before working on anything non-trivial. These
-   guidelines are intended to keep the code consistent and avoid common pitfalls.
+ * Hack away. Please peruse our
+   [style guides](https://flutter.io/style-guide/) and
+   [design principles](https://flutter.io/design-principles/) before
+   working on anything non-trivial. These guidelines are intended to
+   keep the code consistent and avoid common pitfalls.
  * `git commit -a -m "<your brief but informative commit message>"`
  * `git push origin name_of_your_branch`
 

sky/specs/design.md

@@ -1,106 +1,4 @@
 Design Principles
 =================
 
-Flutter is written based on some core principles that were mostly
-intuited from past experiences with other platforms such as the Web
-and Android, some of which are summarised below.
-
-Lazy programming
-----------------
-
-Write what you need and no more, but when you write it, do it right.
-
-Avoid implementing features you don't need. You can't design a feature
-without knowing what the constraints are. Implementing features "for
-completeness" results in unused code that is expensive to maintain,
-learn about, document, test, etc.
-
-When you do implement a feature, implement it the right way. Avoid
-workarounds. Workarounds merely kick the problem further down the
-road, but at a higher cost: someone will have to relearn the problem,
-figure out the workaround and how to dismantle it (and all the places
-that now use it), _and_ implement the feature.
-
-Tests
------
-
-When you fix a bug, first write a test that fails, then fix the bug
-and verify the test passes.
-
-When you implement a new feature, write tests for it.
-
-Run the tests before checking code in. (Travis does this for you, so
-wait for Travis to give the green light before merging a PR.)
-
-API design
-----------
-
-* There should be no objects that represent live state that reflects
-  some other state, since they are expensive to maintain. e.g. no
-  HTMLCollection.
-
-* Property getters should be efficient (e.g. just returning a cached
-  value, or an O(1) table lookup). If an operation is inefficient it
-  should be a method instead. e.g. document.getForms(), not
-  document.forms.
-
-* There should be no APIs that require synchronously completing an
-  expensive operation (e.g. computing a full app layout outside of the
-  layout phase).
-
-* We use a layered framework design, where each layer addresses a
-  narrowly scoped problem and is then used by the next layer to solve
-  a bigger problem. This is true both at a high level (widgets relies
-  on rendering relies on painting) and at the level of individual
-  classes and methods (e.g. in the rendering library, having one class
-  for clipping and one class for opacity rather than one class that
-  does both at the same time).
-
- - Convenience APIs belong at the layer above the one they are
-   simplifying.
-
- - Having dedicated APIs for performance reasons is fine. If one
-   specific operation, say clipping a rounded rectangle, is expensive
-   using the generic API but could be implemented more efficiently
-   using a dedicated API, then a dedicated API is fine.
-
-* APIs that encourage bad practices should not exist. e.g., no
-  document.write(), innerHTML, insertAdjacentHTML(), etc.
-
- - String manipulation to generate data or code that will subsequently
-   be interpreted or parsed is a bad practice as it leads to code
-   injection vulnerabilities.
-
-* If we expose some aspect of a mojo service, we should expose/wrap
-  all of it, so that there's no cognitive cliff when interacting with
-  that service (where you are fine using the exposed API up to a
-  point, but beyond that have to learn all about the underlying
-  service).
-
-Bugs
-----
-
-"Don't lick the cookie": Only assign a bug to yourself when you are
-actively working on it. If you're not working on it, leave it
-unassigned. Don't assign bugs to people unless you know they are going
-to work on it.
-
-File bugs for anything that you come across that needs doing. When you
-implement something but know it's not complete, file bugs for what you
-haven't done. That way, we can keep track of what still needs doing.
-
-Regressions
------------
-
-If a check-in has caused a regression on the trunk, roll back the
-check-in (even if it isn't yours) unless doing so would take longer
-than fixing the bug. When the trunk is broken, it slows down everyone
-else on the project.
-
-There is no shame in making mistakes.
-
-Questions
----------
-
-It's always ok to ask questions. Our systems are large, nobody will be
-an expert in all the systems.
+See [https://flutter.io/design-principles/].