[Chromium] Add PagePopup implementation

[Chromium] Add PagePopup implementation
https://bugs.webkit.org/show_bug.cgi?id=81081

Reviewed by Adam Barth.

Add WebPagePopupImpl class, which is an implementation of
WebCore::PagePopup interface and WebKit::WebPagePopup interface. It's a
WebWidget which has a Page object.

No new tests because this makes no behavior change yet.

* WebKit.gyp: Add WebPagePopupImpl.h.
* src/ChromeClientImpl.cpp:
(WebKit::ChromeClientImpl::hasOpenedPopup): Supports the PagePopup.
(WebKit::ChromeClientImpl::openPagePopup):
just delegate to WebViewImpl::openPagePopup().
(WebKit::ChromeClientImpl::closePagePopup): ditto.

* src/WebPagePopupImpl.cpp:
(PagePopupChromeClient):
This is a light implementation of ChromeClient for the page in
WebPagePopupImpl. This is a friend of WebPagePopupImpl becase of ease of
access to its members.
(WebKit::PagePopupChromeClient::PagePopupChromeClient):
(WebKit::WebPagePopupImpl::WebPagePopupImpl):
(WebKit::WebPagePopupImpl::~WebPagePopupImpl):
(WebKit::WebPagePopupImpl::init):
(WebKit::WebPagePopupImpl::initPage):
(WebKit::WebPagePopupImpl::size):
(WebKit::WebPagePopupImpl::animate): Calls PageWidgetDelegate::animate().
(WebKit::WebPagePopupImpl::composite):
(WebKit::WebPagePopupImpl::layout): Calls PageWidgetDelegate::layout().
(WebKit::WebPagePopupImpl::paint): Calls PageWidgetDelegate::paint().
(WebKit::WebPagePopupImpl::resize):
(WebKit::WebPagePopupImpl::handleKeyEvent):
(WebKit::WebPagePopupImpl::handleCharEvent):
(WebKit::WebPagePopupImpl::handleGestureEvent):
(WebKit::WebPagePopupImpl::handleInputEvent):
(WebKit::WebPagePopupImpl::setFocus):
(WebKit::WebPagePopupImpl::close): Delete the page, and kill itself.
(WebKit::WebPagePopupImpl::closePopup):
(WebKit::WebPagePopup::create):
* src/WebPagePopupImpl.h: Added.

* src/WebViewImpl.cpp:
(WebKit::WebViewImpl::WebViewImpl): Initialize m_pagePopup.
(WebKit::WebViewImpl::handleKeyEvent):
Renamed from keyEvent(). Forward key events to a PagePopup if it is open.
(WebKit::WebViewImpl::handleCharEvent):
Renamed from charEvent(). Forward char events to a PagePopup if it is open.
(WebKit::WebViewImpl::openPagePopup):
Added. Instantiate a WebPagePopupImpl, calculates a good bounding
rectangle of the page popup from the specified element rectangle,
initialize the WebPagePopupImpl, and stop caret blink.
(WebKit::WebViewImpl::closePagePopup):
Close the popup, clear m_pagePopup, and resume caret blink.
(WebKit::WebViewImpl::setFocus): Hide all the popups.
(WebKit::WebViewImpl::hidePopups): Hide the page popup too.
* src/WebViewImpl.h:
(WebKit::WebViewImpl::hasOpenedPopup): Checks the page popup too.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@113956 268f45cc-cd09-0410-ab3c-d52691b4dbfc