Remove device orientation listeners in DOMWindow::willDetachPage

Since DeviceOrientationController is a Page supplement, make sure to
unregister any listeners if the page is going to be detached. Otherwise,
it will be too late to do it in DOMWindow's destructor since page() will
already be null.

BUG=260110

Review URL: https://chromiumcodereview.appspot.com/19430002

git-svn-id: svn://svn.chromium.org/blink/trunk@154359 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Check in pep8.py so that we don't auto-install it.

R=eseidel@chromium.org, ojan@chromium.org
BUG=230706

Review URL: https://chromiumcodereview.appspot.com/19481002

git-svn-id: svn://svn.chromium.org/blink/trunk@154360 bbb929c8-8fbe-4397-9dbb-9b2b20218538
SVGTextMetrics shouldn't use bloatedCharacters

Instead of manually re-implementing substring, we should just call substring.

R=pdr@chromium.org
BUG=254708

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=154272

Review URL: https://chromiumcodereview.appspot.com/19317003

git-svn-id: svn://svn.chromium.org/blink/trunk@154362 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use the async version of WebFileSystem::createFileWriter

Removing unnecessary callback chain.

(Some worker code still rely on the old createFileWriter, but
they're supposed to go away)

This depends on chrome-side patch:
https://codereview.chromium.org/18427005/

BUG=257349
TEST=no behavioral changes

Review URL: https://chromiumcodereview.appspot.com/18411005

git-svn-id: svn://svn.chromium.org/blink/trunk@154363 bbb929c8-8fbe-4397-9dbb-9b2b20218538