Use WebPrivateOwnPtr instead of raw pointer in WebBlobData and WebFilterKeyframe.

WebPrivateOwnPtr requires calling reset() in Blink before WebPrivateOwnPtr is
destructed. Both WebFilterKeyframe and WebBlobData are always destructed in
Blink, so both destructors can call WebPrivateOwnPtr::reset().

initialize() and reset() of WebPrivateOwnPtr are removed because
1. Both are not used.
2. Both makes it hard to use WebPrivateOwnPtr.

Review URL: https://codereview.chromium.org/26729003

git-svn-id: svn://svn.chromium.org/blink/trunk@159775 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Replace check for RenderLayer in RenderLayerModelObject::ensureLayer with ASSERT due to redundant check.

RenderLayerModelObject::styleDidChange() invokes the ensureLayer() method only in case of !layer().
Again checking for layer existence would be deemed redundant in ensureLayer. Replacing it with an
ASSERT(!m_layer).

Review URL: https://codereview.chromium.org/27246003

git-svn-id: svn://svn.chromium.org/blink/trunk@159776 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove web/{android, gtk, win}

The {android, gtk, win} directories contain only WebInputEventFactory.cpp. We can just move these files to web/ with files renamed as WebInputEventFactoryAndroid.cpp,
WebInputEventFactoryGtk.cpp, WebInputEventFactoryWin.cpp respectively and remove the dir.
Moved the WebInputEventFactory.mm also to web/ but since web/mac/ still contains one more file, retained the dir. Probably can move the file also to web/ and remove the dir.

BUG=None

TEST=None;no behavior changes;

Review URL: https://codereview.chromium.org/27462002

git-svn-id: svn://svn.chromium.org/blink/trunk@159777 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Refactoring: Delete DatabaseBackendContext

This change merges DatabaseBackendContext to DatabaseContext as
the former is doing almost nothing.

This also eliminates dependency from core/ to DatabaseManager.h.
The dependency was there just because keeping the context's lifetime
which can be implemented using a LifecycleObserver callback.

BUG=none
TEST=none
R=abarth

Review URL: https://codereview.chromium.org/27483004

git-svn-id: svn://svn.chromium.org/blink/trunk@159778 bbb929c8-8fbe-4397-9dbb-9b2b20218538