Mark layers that can use LCD text based on layer transform and opacity.

cc/layer_tree_host.cc

Index: cc/layer_tree_host.cc
diff --git a/cc/layer_tree_host.cc b/cc/layer_tree_host.cc
index 0d7da692d6f47a23dc30d03f56e74a7d13e92218..8c43d75995d21d3037678aafa3612b70fc80be69 100644
--- a/cc/layer_tree_host.cc
+++ b/cc/layer_tree_host.cc
@@ -47,12 +47,18 @@ LayerTreeSettings::LayerTreeSettings()
     , showReplicaScreenSpaceRects(false)
     , showOccludingRects(false)
     , renderVSyncEnabled(true)
+    , canUseLCDText(true)
     , refreshRate(0)
     , maxPartialTextureUpdates(std::numeric_limits<size_t>::max())
     , defaultTileSize(gfx::Size(256, 256))
     , maxUntiledLayerSize(gfx::Size(512, 512))
     , minimumOcclusionTrackingSize(gfx::Size(160, 160))
 {
+// FIXME: Remove this hard-coded setting.
+// Platforms that need to disable LCD text must explicitly set this value.
+#if OS(ANDROID)
+    canUseLCDText = false;
+#endif
 }
 
 LayerTreeSettings::~LayerTreeSettings()
@@ -548,7 +554,7 @@ void LayerTreeHost::updateLayers(Layer* rootLayer, ResourceUpdateQueue& queue)
         }
 
         TRACE_EVENT0("cc", "LayerTreeHost::updateLayers::calcDrawEtc");
-        LayerTreeHostCommon::calculateDrawTransforms(rootLayer, deviceViewportSize(), m_deviceScaleFactor, m_pageScaleFactor, rendererCapabilities().maxTextureSize, updateList);
+        LayerTreeHostCommon::calculateDrawTransforms(rootLayer, deviceViewportSize(), m_deviceScaleFactor, m_pageScaleFactor, rendererCapabilities().maxTextureSize, m_settings.canUseLCDText, updateList);
     }
 
     // Reset partial texture update requests.