[DOM4] Doctypes now always have a node document and can be moved across document boundaries

Doctypes now always have a node document and can be moved across document boundaries as per
the latest DOM4 specification:
http://dom.spec.whatwg.org/#dom-domimplementation-createdocumenttype
http://dom.spec.whatwg.org/#dom-node-ownerdocument

This means that DOMImplementation.createDocumentType() now sets the ownerDocument of the
new DocumentType Node to the associated document of the current "context" object. In
DOM4, all nodes have a document at all times. DocumentType nodes can now be moved across
document boundaries so that the node can be added to a Document after being created.

Firefox stable already follows DOM4 here while IE10 does not (yet).

BUG=275600

Review URL: https://chromiumcodereview.appspot.com/22880019

git-svn-id: svn://svn.chromium.org/blink/trunk@156581 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Merge FrameLoader::stopLoading into stopAllLoaders

FrameLoader::stopLoading is called twice:
* From FrameLoader::closeURL after the unload event, when the relevant document is about to disappear and is going to get cleaned up anyway.
* From DocumentLoader::stopLoading in the case where the document is committed. The only time this occurs is within FrameLoader::stopAllLoaders.

BUG=none

Review URL: https://chromiumcodereview.appspot.com/23361010

git-svn-id: svn://svn.chromium.org/blink/trunk@156582 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Spell check whole content of an editable element when it gets focused.

This is how Gecko and Presto behave. Without this patch Blink spell checks
an editable after moving the caret/unfocusing the editable but the check spans
only the line the caret was previously at (possibly plus 1-2 lines around).
Textareas and contenteditables are only spell checked on
first focus.

BUG=264730

Review URL: https://chromiumcodereview.appspot.com/21694005

git-svn-id: svn://svn.chromium.org/blink/trunk@156583 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Return font data synchronously on memoy cache hit.

We recently switched cache hits to return data asychronously by default.
Doing so for fonts caused a performance regression on barnesandnoble.com

BUG=276963
TEST=typical_25 PLT

Review URL: https://chromiumcodereview.appspot.com/22929025

git-svn-id: svn://svn.chromium.org/blink/trunk@156584 bbb929c8-8fbe-4397-9dbb-9b2b20218538
fillContainerFromString should attach lazily.

Review URL: https://chromiumcodereview.appspot.com/23003025

git-svn-id: svn://svn.chromium.org/blink/trunk@156585 bbb929c8-8fbe-4397-9dbb-9b2b20218538