Refactoring: Introduce ResouceLoaderHost interface for unloading ResourceLoader.

This moves several direct dependencies of ResourceLoader into
newly inroduced ResouceLoaderHost interface, which is implemented by
CachedResourceLoader.

The motivation here is to make ResourceLoader working without DocumentLoader
and FrameLoader so that scripts can be loaded through imported documents, which
doesn't have a DocumentLoader.

Note that CachedResourceLoader already lives without DocumentLoader in some case,
thus it is natural to localize such kind of complication there and keep ResourceLoader
straightforward.

BUG=240592
TEST=none
R=japhet@chromium.org

Review URL: https://codereview.chromium.org/19574002

git-svn-id: svn://svn.chromium.org/blink/trunk@154452 bbb929c8-8fbe-4397-9dbb-9b2b20218538
WebFrameImpl shouldn't use bloatedCharacters

Instead, it should use appendTextToStringBuilder.

R=eseidel
BUG=254708

Review URL: https://chromiumcodereview.appspot.com/19572010

git-svn-id: svn://svn.chromium.org/blink/trunk@154453 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move some Device Orientation bits from core/dom to modules/device_orientation

This CL moves a number of files for Device Orientation to where they should be, i.e. modules/device_orientation. This is in preparation for a larger refactoring to implement Device Orientation using the platform approach and hence unifying it with the Device Motion implementation.

BUG=261165

Review URL: https://chromiumcodereview.appspot.com/19644003

git-svn-id: svn://svn.chromium.org/blink/trunk@154454 bbb929c8-8fbe-4397-9dbb-9b2b20218538