Handle overflow detection in WebGLRenderingContext.

BUG=328203
TEST=

Review URL: https://codereview.chromium.org/101463007

git-svn-id: svn://svn.chromium.org/blink/trunk@164554 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Auto-rebaseline for r163715

http://src.chromium.org/viewvc/blink?view=revision&revision=163715

BUG=325987
TBR=shawnsingh@chromium.org

Review URL: https://codereview.chromium.org/125843002

git-svn-id: svn://svn.chromium.org/blink/trunk@164555 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move line/float offset functions to RenderBlockFlow

The base RenderBlock class shouldn't have any line/float logic. This
patch moves line/float offset functions to RenderBlockFlow. Previously,
logical[Left|Right]FloatOffsetForLine used virtual dispatch; moving
the virtual logic down to logical[Left|Right]SelectionOffset, and
tightening up callers to the float methods.

BUG=302024

Review URL: https://codereview.chromium.org/101843006

git-svn-id: svn://svn.chromium.org/blink/trunk@164556 bbb929c8-8fbe-4397-9dbb-9b2b20218538