[chromium] Support CCHeadsUpDisplay in threaded compositing mode

[chromium] Support CCHeadsUpDisplay in threaded compositing mode
https://bugs.webkit.org/show_bug.cgi?id=67499

Reviewed by James Robinson.

No new tests because this code is debugging code itself.

The last item that was needed to make the CCHeadsUpDisplay work in
threaded compositing mode was to remove the font rendering code
used on the impl-side thread. To solve this, this patch adds a
CCFontAtlas that is initialized on the main thread (where the font
rendering takes place). Then, when the HUD draws text on the impl
thread, it uses the font atlas directly.

* WebCore.gypi:
* platform/graphics/chromium/LayerRendererChromium.cpp:
(WebCore::LayerRendererChromium::create):
(WebCore::LayerRendererChromium::initialize):
* platform/graphics/chromium/LayerRendererChromium.h:
(WebCore):
(LayerRendererChromium):
* platform/graphics/chromium/cc/CCFontAtlas.cpp: Added.
(WebCore):
(WebCore::CCFontAtlas::CCFontAtlas):
(WebCore::wrapPositionIfNeeded):
(WebCore::CCFontAtlas::generateAtlasForFont):
(WebCore::CCFontAtlas::initialize):
(WebCore::CCFontAtlas::drawText):
(WebCore::CCFontAtlas::drawOneLineOfTextInternal):
(WebCore::CCFontAtlas::drawDebugAtlas):
* platform/graphics/chromium/cc/CCFontAtlas.h: Added.
(WebCore):
(CCFontAtlas):
(WebCore::CCFontAtlas::create):
* platform/graphics/chromium/cc/CCHeadsUpDisplay.cpp:
(WebCore::CCHeadsUpDisplay::CCHeadsUpDisplay):
(WebCore):
(WebCore::CCHeadsUpDisplay::showPlatformLayerTree):
(WebCore::CCHeadsUpDisplay::drawHudContents):
(WebCore::CCHeadsUpDisplay::drawFPSCounter):
(WebCore::CCHeadsUpDisplay::drawFPSCounterText):
(WebCore::CCHeadsUpDisplay::drawPlatformLayerTree):
* platform/graphics/chromium/cc/CCHeadsUpDisplay.h:
(WebCore::CCHeadsUpDisplay::create):
(CCHeadsUpDisplay):
* platform/graphics/chromium/cc/CCLayerTreeHost.cpp:
(WebCore::CCLayerTreeHost::initialize):
* platform/graphics/chromium/cc/CCLayerTreeHost.h:
(WebCore):
(WebCore::CCLayerTreeHost::headsUpDisplayFontAtlas):
(CCLayerTreeHost):
* platform/graphics/chromium/cc/CCLayerTreeHostImpl.cpp:
(WebCore::CCLayerTreeHostImpl::initializeLayerRenderer):
* platform/graphics/chromium/cc/CCLayerTreeHostImpl.h:
(WebCore):
(CCLayerTreeHostImpl):
* platform/graphics/chromium/cc/CCSingleThreadProxy.cpp:
(WebCore::CCSingleThreadProxy::initializeLayerRenderer):
(WebCore::CCSingleThreadProxy::recreateContext):
* platform/graphics/chromium/cc/CCThreadProxy.cpp:
(WebCore::CCThreadProxy::initializeLayerRendererOnImplThread):
(WebCore::CCThreadProxy::recreateContextOnImplThread):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114147 268f45cc-cd09-0410-ab3c-d52691b4dbfc