Fold WidgetChromium.cpp into Widget.cpp, and remove unnecessary methods.

Based on https://codereview.chromium.org/14222006/

Review URL: https://chromiumcodereview.appspot.com/14135013

git-svn-id: svn://svn.chromium.org/blink/trunk@149284 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove USE(3D_GRAPHICS) as it is always turned on.

Review URL: https://chromiumcodereview.appspot.com/14398007

git-svn-id: svn://svn.chromium.org/blink/trunk@149285 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make resize-events test platform-independent.

resize-events test checks whether a resize event is fired or not. An only text
test can satisfy the purpose of this test. This patch simplifies this test to
maintain this test easily.

BUG=

Review URL: https://chromiumcodereview.appspot.com/14518004

git-svn-id: svn://svn.chromium.org/blink/trunk@149286 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove unused CPU() guards.

Review URL: https://chromiumcodereview.appspot.com/14398006

git-svn-id: svn://svn.chromium.org/blink/trunk@149287 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [CodeMirror] selected text is not rendered

In some cases the RenderTheme provides
with an invalid selection color; this patch handles this case.

BUG=234633

Review URL: https://chromiumcodereview.appspot.com/14200039

git-svn-id: svn://svn.chromium.org/blink/trunk@149289 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove OS(IOS) and OS(MAC_OS_X) guards.

OS(IOS) is not supported.
OS(MAC_OS_X) is replaced with OS(DARWIN).

Review URL: https://chromiumcodereview.appspot.com/14516007

git-svn-id: svn://svn.chromium.org/blink/trunk@149291 bbb929c8-8fbe-4397-9dbb-9b2b20218538