Revert "Make compositingState explicit (re-land with bogus ASSERT removed)"

This reverts commit 2a33ee04f3cb493d3081ef700fb12d6344c39cd4.

This change is hitting
"ASSERTION FAILED: layerChanged == compositingStateChanged"
in 100+ debug tests.

TBR=shawnsingh@chromium.org
NOTRY=TRUE

Review URL: https://codereview.chromium.org/26470002

git-svn-id: svn://svn.chromium.org/blink/trunk@159108 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: [Custom] and [CustomGetter] getters (+ fix Perl [Custom] readonly)

This also fixes a bug in the Perl CG:
For [Custom] readonly attributes: the Perl CG generates
a setter (*AttributeSetterCustom) in the header, which is incorrect,
since readonly attributes can't be set.

Compare for instance:
Source/core/events/Event.idl
[Custom] readonly attribute Clipboard clipboardData;

Source/bindings/v8/custom/V8EventCustom.cpp
...which doesn't implement the setter.

Also consistency changes in IDLs:
[Custom] => [CustomGetter] for read only (and not [Replaceable]) attributes
[CustomGetter, CustomSetter] => [Custom]

Doc:
https://sites.google.com/a/chromium.org/dev/blink/webidl/blink-idl-extended-attributes#TOC-Custom-m-a-CustomGetter-a-CustomSetter-a-

BUG=239771

Review URL: https://codereview.chromium.org/26420002

git-svn-id: svn://svn.chromium.org/blink/trunk@159109 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[DevTools] Use device metrics emulation implemented in content.

Device emulation is now split: while metrics emulation is simply forwarded
to embedder, a number of internal blink settings are set to emulate device
behavior. These settings include overlay scrollbars, viewport support, text
autosizing and page scaling.

To support fit-to-window mode, WebView now sets a scaling transform
to the root graphics layer. Also, device scale factor is overriden to produce
sharp image even when emulating.

This also removes old device metrics emulation support through blink code.

See also Chromium-side patch: https://codereview.chromium.org/23364004/

BUG=288959
R=aelias@chromium.org, pfeldman@chromium.org

Review URL: https://codereview.chromium.org/23187005

git-svn-id: svn://svn.chromium.org/blink/trunk@159110 bbb929c8-8fbe-4397-9dbb-9b2b20218538