https://bugs.webkit.org/show_bug.cgi?id=83681

Reviewed by Anders Carlsson.

Add WebKitWebPage::send-request signal emitted in willSendRequest
callback to allow web process extensions to modify requests before
they are sent or cancel the resource load.
This patch makes WebKitURIRequest and WebKitURIResponse objects
shareable between UI process and web extensions APIs. Since both
APIs force single header includes, the WebKitDefines.h header has
been split moving the forward declarations specific to the UI
process API to a new file WebKitForwardDeclarations.h. This way we
can also  share the WebKitDefines.h header and remove the
WebKitWebExtensionDefines.h header used in the web extensions API.

* GNUmakefile.list.am: Add new files to compilation.
* UIProcess/API/gtk/WebKitContextMenu.h: Include WebKitForward.h.
* UIProcess/API/gtk/WebKitContextMenuItem.h: Ditto.
* UIProcess/API/gtk/WebKitDefines.h: Remove forward declarations.
* UIProcess/API/gtk/WebKitDownload.h: Include WebKitForward.h.
* UIProcess/API/gtk/WebKitFindController.h: Ditto.
* UIProcess/API/gtk/WebKitForwardDeclarations.h: Added. Contains
the forward declarations moved from WebKitDefines.h.
* UIProcess/API/gtk/WebKitPrintOperation.h: Include WebKitForward.h.
* UIProcess/API/gtk/WebKitURIRequest.cpp:
(webkitURIRequestSetProperty): Use webkit_uri_request_set_uri() to
set the new URI.
(webkit_uri_request_class_init): Make URI property construct
instead of construct-only, since it can be updated once
constructed. It should never be NULL, so set default value to
about:blank instad of NULL.
(webkit_uri_request_set_uri): New public method to set the URI of
the WebKitURIRequest.
* UIProcess/API/gtk/WebKitURIRequest.h: Allow to include this file
from webkit-web-extension.h.
* UIProcess/API/gtk/WebKitURIResponse.h: Ditto.
* UIProcess/API/gtk/WebKitURISchemeRequest.h: Include
WebKitForward.h.
* UIProcess/API/gtk/WebKitWebView.h: Ditto.
* UIProcess/API/gtk/docs/webkit2gtk-sections.txt: Add
webkit_uri_request_set_uri.
* UIProcess/API/gtk/tests/TestResources.cpp:
(testWebResourceSendRequest):
(serverCallback):
(beforeAll):
* UIProcess/API/gtk/tests/WebExtensionTest.cpp:
(sendRequestCallback):
(pageCreatedCallback):
* UIProcess/API/gtk/webkit2marshal.list:
* WebProcess/InjectedBundle/API/gtk/WebKitWebExtension.h: Include
WebKitDefines.h instead of WebKitWebExtensionDefines.h.
* WebProcess/InjectedBundle/API/gtk/WebKitWebPage.cpp:
(willSendRequestForFrame): Emit WebKitWebPage::send-request and
return early if the load is cancelled.
(webkit_web_page_class_init): Add WebKitWebPage::send-request
signal.
* WebProcess/InjectedBundle/API/gtk/WebKitWebPage.h: Include
WebKitDefines.h instead of WebKitWebExtensionDefines.h.
* WebProcess/InjectedBundle/API/gtk/webkit-web-extension.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148679 268f45cc-cd09-0410-ab3c-d52691b4dbfc