Handle lost graphics contexts in Canvas2DLayerBridge creation

BUG=335926

Review URL: https://codereview.chromium.org/145583010

git-svn-id: svn://svn.chromium.org/blink/trunk@165971 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Added field to error structures to signal existence of a stale copy in
the cache, for use by the navigation source.

BUG=329620

Review URL: https://codereview.chromium.org/138493002

git-svn-id: svn://svn.chromium.org/blink/trunk@165973 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix repainting of line layout when repaint-after-layout is enabled.

The CL https://src.chromium.org/viewvc/blink?view=rev&revision=165800 changed
how the line layouts re-repainted. This CL adds in the needed updates for the
new code to work with repaint-after-layout.

BUG=336253

Review URL: https://codereview.chromium.org/148333008

git-svn-id: svn://svn.chromium.org/blink/trunk@165974 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Introduce isOverflowVisible()

Since it's illegal for overflowX() to be OVISIBLE and for
overflowY() to be something else (and vice versa), create a
helper function that ASSERTs this and removes the need to
write statements that look wrong to the uninitiated!

BUG=

Review URL: https://codereview.chromium.org/145003016

git-svn-id: svn://svn.chromium.org/blink/trunk@165975 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make RenderObject::adjustStyleDifference abort early for Text (and make the function more clear)

This function had a bunch of confusing cases in it, lets start by making
it clear that for Text we don't need to do most of the work. I also switched
to using <= instead of < for a bunch of cases to make it more obvious what
conditions this code is for.

BUG=335703

Review URL: https://codereview.chromium.org/148463012

git-svn-id: svn://svn.chromium.org/blink/trunk@165976 bbb929c8-8fbe-4397-9dbb-9b2b20218538