https://bugs.webkit.org/show_bug.cgi?id=86051

Reviewed by James Robinson.

Source/Platform:

* chromium/public/WebLayerTreeView.h:
(WebKit::WebLayerTreeView::Settings::Settings):
(Settings):

Source/WebCore:

On initialization, give the defaultDeviceScaleFactor to the compositor
to have it scale all output from WebCore's layout size to physical
pixels. This allows us to scale up to high-dpi devices without using
fixed-layout, so we can leave the WebCore frame size in layout pixels,
while drawing the frame into a larger physical pixel size.

CCLayerTreeHost becomes aware of the deviceScaleFactor and scales all
output by this factor by scaling the viewport and all drawing
transforms.

Anything that works in physical pixels (content space), uses the
deviceViewportSize() in place of the viewportSize(), since when
deviceScaleFactor != 1 in CCLayerTreeHost, the WebCore viewport
is no longer physical pixels.

Scroll positions are in layout pixels, and must be scaled to/from
content space within the compositor.

Unit tests: CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers

* platform/graphics/chromium/LayerRendererChromium.h:
(LayerRendererChromiumClient):
(WebCore::LayerRendererChromium::viewportSize):
(WebCore::LayerRendererChromium::viewportWidth):
(WebCore::LayerRendererChromium::viewportHeight):
(LayerRendererChromium):
* platform/graphics/chromium/cc/CCLayerTreeHost.cpp:
(WebCore::CCLayerTreeHost::initializeLayerRenderer):
(WebCore::CCLayerTreeHost::setViewportSize):
(WebCore::CCLayerTreeHost::updateLayers):
(WebCore::CCLayerTreeHost::paintLayerContents):
* platform/graphics/chromium/cc/CCLayerTreeHost.h:
(WebCore::CCSettings::CCSettings):
(CCSettings):
(CCLayerTreeHost):
(WebCore::CCLayerTreeHost::deviceViewportSize):
* platform/graphics/chromium/cc/CCLayerTreeHostImpl.cpp:
(WebCore::CCLayerTreeHostImpl::calculateRenderSurfaceLayerList):
(WebCore::CCLayerTreeHostImpl::calculateRenderPasses):
(WebCore::CCLayerTreeHostImpl::setViewportSize):
(WebCore::CCLayerTreeHostImpl::updateMaxScrollPosition):
(WebCore::CCLayerTreeHostImpl::scrollBegin):
(WebCore::CCLayerTreeHostImpl::computePinchZoomDeltas):
* platform/graphics/chromium/cc/CCLayerTreeHostImpl.h:
(WebCore::CCLayerTreeHostImpl::viewportSize):
(CCLayerTreeHostImpl):

Source/WebKit/chromium:

Add the applyDefaultDeviceScaleInCompositor setting. When enabled, we
apply the scale factor during compositing instead of applying it through
the pageScaleFactor.

NonCompositedContentHost is the GraphicLayerClient for the GraphicsLayer
containing the document's body. It needs to report the page/device scale
that should be used when scaling the contents of the GraphicsLayer, and
when changes occur to them such that its contentsSize or contentsScale
is affected.

Store the deviceScaleFactor being used in the compositor. The remainder
of the deviceScaleFactor() is being applied to the pageScale.

* public/WebSettings.h:
* src/NonCompositedContentHost.cpp:
(WebKit::NonCompositedContentHost::NonCompositedContentHost):
(WebKit::NonCompositedContentHost::setViewport):
* src/NonCompositedContentHost.h:
(NonCompositedContentHost):
* src/WebLayerTreeView.cpp:
(WebKit::WebLayerTreeView::Settings::operator CCSettings):
* src/WebSettingsImpl.cpp:
(WebKit::WebSettingsImpl::setApplyDefaultDeviceScaleFactorInCompositor):
(WebKit):
* src/WebSettingsImpl.h:
(WebSettingsImpl):
(WebKit::WebSettingsImpl::applyDefaultDeviceScaleFactorInCompositor):
* src/WebViewImpl.cpp:
(WebKit::WebViewImpl::WebViewImpl):
(WebKit::WebViewImpl::setPageScaleFactor):
(WebKit::WebViewImpl::setDeviceScaleFactor):
(WebKit::WebViewImpl::enableFixedLayoutMode):
(WebKit::WebViewImpl::computePageScaleFactorLimits):
(WebKit::WebViewImpl::setIsAcceleratedCompositingActive):
(WebKit::WebViewImpl::updateLayerTreeViewport):
* src/WebViewImpl.h:
* tests/CCLayerTreeHostTest.cpp:
(MockLayerTreeHostImpl):
(WTF::MockLayerTreeHost::createLayerTreeHostImpl):
(CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers):
(WTF::CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers::CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers):
(WTF::CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers::beginTest):
(WTF::CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers::commitCompleteOnCCThread):
(WTF::CCLayerTreeHostTestDeviceScaleFactorScalesViewportAndLayers::afterTest):
(WTF):
(WTF::TEST_F):
* tests/LayerRendererChromiumTest.cpp:
* tests/WebFrameTest.cpp:
(WebKit::TEST_F):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@117535 268f45cc-cd09-0410-ab3c-d52691b4dbfc