https://bugs.webkit.org/show_bug.cgi?id=74376

Reviewed by Kenneth Russell.

Source/WebCore:

CCLayerDelegate::notifySyncRequired is an odd bit of interface that we originally cargo-culted from the
CoreAnimation compositor implementation. It is a mechanism by which a LayerChromium instance may request a new
frame via its CCLayerDelegate, which in WebCore is always a GraphicsLayerClient. In practice, all
implementations eventually ended up routing to CCLayerTreeHost::setNeedsCommit which then made the proper
scheduling decision.

This patch routes all changes that would have gone through CCLayerDelegate::notifySyncRequired directly to
CCLayerTreeHost::setNeedsCommit, which greatly simplifies the scheduling logic.

There is a large amount of unit test coverage for this change, largely in LayerChromiumTest

* platform/graphics/chromium/GraphicsLayerChromium.cpp:
* platform/graphics/chromium/GraphicsLayerChromium.h:
* platform/graphics/chromium/LayerChromium.cpp:
(WebCore::LayerChromium::setNeedsCommit):
(WebCore::LayerChromium::insertChild):
* platform/graphics/chromium/LayerChromium.h:
* platform/graphics/chromium/cc/CCLayerTreeHost.cpp:
(WebCore::CCLayerTreeHost::~CCLayerTreeHost):
(WebCore::CCLayerTreeHost::setRootLayer):
* platform/graphics/chromium/cc/CCLayerTreeHost.h:
* platform/graphics/chromium/cc/CCScopedThreadProxy.h:
(WebCore::CCScopedThreadProxy::runTaskIfNotShutdown):

Source/WebKit/chromium:

WebLayerClient::notifyNeedsComposite() is an odd interface for the same reason that
CCLayerDelegate::notifySyncRequired() is - all scheduling decisions should route through the WebLayerTreeView,
not individual layers. In practice, all implementations of WebLayerClient::notifySyncRequired() do the exact
same thing as WebLayerTreeView::scheduleComposite(). This removes that callback, making WebLayerClient an empty
interface, and routes all calls that would go to that interface to WebLayerTreeView::scheduleComposite().

Once downstream implementations of WebLayerClient are removed, WebLayerClient.h and the constructors associated
with it can be deleted.

The bulk of the changes here are to the test harness. Many tests that were designed around notifySyncRequired()
are rewritten to check for CCLayerTreeHost::setNeedsCommit() or WebLayerTreeView::scheduleComposite() instead.
In a few instances, this required changing the setup logic around somewhat so that the layers being manipulated
were in a tree that initialized without errors.

* WebKit.gypi:
* public/platform/WebContentLayer.h:
* public/platform/WebExternalTextureLayer.h:
* public/platform/WebLayer.h:
* public/platform/WebLayerClient.h:
* src/WebContentLayer.cpp:
(WebKit::WebContentLayer::create):
* src/WebContentLayerImpl.cpp:
(WebKit::WebContentLayerImpl::create):
(WebKit::WebContentLayerImpl::WebContentLayerImpl):
* src/WebContentLayerImpl.h:
* src/WebExternalTextureLayer.cpp:
(WebKit::WebExternalTextureLayer::create):
* src/WebExternalTextureLayerImpl.cpp:
(WebKit::WebExternalTextureLayerImpl::create):
(WebKit::WebExternalTextureLayerImpl::WebExternalTextureLayerImpl):
* src/WebExternalTextureLayerImpl.h:
* src/WebLayer.cpp:
(WebKit::WebLayer::create):
* src/WebLayerImpl.cpp:
(WebKit::WebLayerImpl::create):
(WebKit::WebLayerImpl::WebLayerImpl):
* src/WebLayerImpl.h:
* src/WebLayerTreeViewImpl.cpp:
(WebKit::WebLayerTreeViewImpl::create):
(WebKit::WebLayerTreeViewImpl::WebLayerTreeViewImpl):
* src/WebLayerTreeViewImpl.h:
* tests/CCLayerTreeHostTest.cpp:
(WTF::MockLayerTreeHost::create):
(WTF::MockLayerTreeHost::MockLayerTreeHost):
(WTF::MockLayerTreeHostClient::createLayerTreeHostContext3D):
(WTF::CCLayerTreeHostTestScrollSimple::animateAndLayout):
* tests/CompositorMockGraphicsContext3D.h: Added.
(WebCore::createCompositorMockGraphicsContext3D):
* tests/CompositorMockWebGraphicsContext3D.h: Added.
(WebKit::CompositorMockWebGraphicsContext3D::create):
(WebKit::CompositorMockWebGraphicsContext3D::makeContextCurrent):
(WebKit::CompositorMockWebGraphicsContext3D::createProgram):
(WebKit::CompositorMockWebGraphicsContext3D::createShader):
(WebKit::CompositorMockWebGraphicsContext3D::getShaderiv):
(WebKit::CompositorMockWebGraphicsContext3D::getProgramiv):
(WebKit::CompositorMockWebGraphicsContext3D::CompositorMockWebGraphicsContext3D):
* tests/LayerChromiumTest.cpp:
* tests/MockWebGraphicsContext3D.h:
(WebKit::MockWebGraphicsContext3D::getContextAttributes):
* tests/WebGLLayerChromiumTest.cpp:
(WebKit::TEST):
* tests/WebLayerTest.cpp:
(testing::MockWebLayerTreeViewClient::animateAndLayout):
(testing::MockWebLayerTreeViewClient::applyScrollAndScale):
(testing::MockWebLayerTreeViewClient::createContext3D):
(testing::MockWebLayerTreeViewClient::didRebindGraphicsContext):
(testing::WebLayerTest::SetUp):
(testing::WebLayerTest::TearDown):
(testing::TEST_F):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@103293 268f45cc-cd09-0410-ab3c-d52691b4dbfc