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

cc/content_layer_unittest.cc

Index: cc/content_layer_unittest.cc
diff --git a/cc/content_layer_unittest.cc b/cc/content_layer_unittest.cc
index c7f32bec60fd0d7cf6726a59c3f7f9ac6db5b520..4a0ab233a42a6b1fab29ab7a0c3ebd3f3252eb7b 100644
--- a/cc/content_layer_unittest.cc
+++ b/cc/content_layer_unittest.cc
@@ -7,6 +7,7 @@
 #include "cc/bitmap_content_layer_updater.h"
 #include "cc/content_layer_client.h"
 #include "cc/rendering_stats.h"
+#include "cc/resource_update_queue.h"
 #include "cc/test/geometry_test_utils.h"
 #include "skia/ext/platform_canvas.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -17,6 +18,25 @@ using namespace WebKit;
 namespace cc {
 namespace {
 
+class FakeContentLayer : public ContentLayer {
+public:
+    explicit FakeContentLayer(ContentLayerClient* client) : ContentLayer(client) { }
+
+    virtual void setNeedsDisplayRect(const gfx::RectF& dirtyRect) OVERRIDE
+    {
+        m_lastDirtyRect = dirtyRect;
+        ContentLayer::setNeedsDisplayRect(dirtyRect);
+    }
+    gfx::RectF lastDirtyRect() const { return m_lastDirtyRect; }
+
+protected:
+    virtual ~FakeContentLayer() { }
+    virtual void createUpdaterIfNeeded() OVERRIDE { }
+
+private:
+    gfx::RectF m_lastDirtyRect;
+};
+
 class MockContentLayerClient : public ContentLayerClient {
 public:
     explicit MockContentLayerClient(gfx::Rect opaqueLayerRect)
@@ -49,5 +69,59 @@ TEST(ContentLayerTest, ContentLayerPainterWithDeviceScale)
     EXPECT_RECT_EQ(gfx::ToEnclosingRect(opaqueRectInContentSpace), resultingOpaqueRect);
 }
 
+TEST(ContentLayerTest, CanUseLCDTextEnableCount)
+{
+    scoped_refptr<FakeContentLayer> layer = new FakeContentLayer(NULL);
+    layer->setBounds(gfx::Size(100, 100));
+    ResourceUpdateQueue queue;
+    RenderingStats stats;
+
+    // By default LCD text is disabled.
+    EXPECT_FALSE(layer->canUseLCDText());
+
+    // LCD text can be enabled once.
+    layer->drawProperties().can_use_lcd_text = true;
+    layer->update(queue, NULL, stats);
+    EXPECT_TRUE(layer->canUseLCDText());
+
+    // LCD text can always be disabled.
+    layer->drawProperties().can_use_lcd_text = false;
+    layer->update(queue, NULL, stats);
+    EXPECT_FALSE(layer->canUseLCDText());
+
+    // LCD text cannot be enabled anymore.
+    layer->drawProperties().can_use_lcd_text = true;
+    layer->update(queue, NULL, stats);
+    EXPECT_FALSE(layer->canUseLCDText());
+}
+
+TEST(ContentLayerTest, CanUseLCDTextChangeTriggersRepaint)
+{
+    scoped_refptr<FakeContentLayer> layer = new FakeContentLayer(NULL);
+    layer->setBounds(gfx::Size(100, 100));
+    gfx::RectF dirtyRect(100, 100);
+    ResourceUpdateQueue queue;
+    RenderingStats stats;
+
+    // By default LCD text is disabled.
+    EXPECT_FALSE(layer->canUseLCDText());
+
+    // Enable LCD text and verify that it triggers invalidation.
+    layer->drawProperties().can_use_lcd_text = true;
+    layer->update(queue, NULL, stats);
+    EXPECT_TRUE(layer->canUseLCDText());
+    EXPECT_EQ(dirtyRect, layer->lastDirtyRect());
+
+    // Reset dirty rect.
+    layer->setNeedsDisplayRect(gfx::RectF());
+    EXPECT_EQ(gfx::RectF(), layer->lastDirtyRect());
+
+    // Disable LCD text and verify that it triggers invalidation.
+    layer->drawProperties().can_use_lcd_text = false;
+    layer->update(queue, NULL, stats);
+    EXPECT_FALSE(layer->canUseLCDText());
+    EXPECT_EQ(dirtyRect, layer->lastDirtyRect());
+}
+
 }  // namespace
 }  // namespace cc