Expose IsSolidColor and write units tests

cc/resources/picture_pile_unittest.cc

Index: cc/resources/picture_pile_unittest.cc
diff --git a/cc/resources/picture_pile_unittest.cc b/cc/resources/picture_pile_unittest.cc
index 31e0a2a32f638eeb77b907142139dacbeb36f6eb..39a32376aebbf364dfcc8aa59db9e2fcd9e0a581 100644
--- a/cc/resources/picture_pile_unittest.cc
+++ b/cc/resources/picture_pile_unittest.cc
@@ -39,13 +39,16 @@ class TestPicturePile : public PicturePile {
 class PicturePileTest : public testing::Test {
  public:
   PicturePileTest()
-      : pile_(new TestPicturePile()),
-        background_color_(SK_ColorBLUE),
+      : background_color_(SK_ColorBLUE),
         min_scale_(0.125),
         frame_number_(0),
-        contents_opaque_(false) {
+        contents_opaque_(false) {}
+
+  virtual void SetUp() OVERRIDE {
+    pile_ = make_scoped_refptr(new TestPicturePile());
     pile_->SetTileGridSize(gfx::Size(1000, 1000));
     pile_->SetMinContentsScale(min_scale_);
+    client_ = FakeContentLayerClient();
     SetTilingSize(pile_->tiling().max_texture_size());
   }
 
@@ -1003,5 +1006,51 @@ TEST_F(PicturePileTest, SmallResizePileInsideInterestRect) {
   invalidation.Clear();
 }
 
+TEST_F(PicturePileTest, SolidRectangleIsSolid) {
+  // If the client has no contents, the solid state will be true
+  Region invalidation1(tiling_rect());
+  UpdateAndExpandInvalidation(&invalidation1, tiling_size(), tiling_rect());
+  EXPECT_TRUE(pile_->IsSolidColor());
+  EXPECT_EQ(SK_ColorTRANSPARENT, pile_->GetSolidColor());
+
+  // If there is a single rect that covers the view, the solid
+  // state will be true
+  SkPaint paint;
+  paint.setColor(SK_ColorCYAN);
+  client_.add_draw_rect(tiling_rect(), paint);
+  Region invalidation2(tiling_rect());
+  UpdateAndExpandInvalidation(&invalidation2, tiling_size(), tiling_rect());
+  EXPECT_TRUE(pile_->IsSolidColor());
+  EXPECT_EQ(SK_ColorCYAN, pile_->GetSolidColor());
+
+  // if a second smaller rect is draw that doesn't cover the viewport
+  // completely, the solid state will be false
+  gfx::Rect smallRect = tiling_rect();
+  smallRect.Inset(10, 10, 10, 10);
+  client_.add_draw_rect(smallRect, paint);
+  Region invalidation3(tiling_rect());
+  UpdateAndExpandInvalidation(&invalidation3, tiling_size(), tiling_rect());
+  EXPECT_FALSE(pile_->IsSolidColor());
+
+  // if a third rect is drawn over everything, we should be solid again
+  paint.setColor(SK_ColorRED);
+  client_.add_draw_rect(tiling_rect(), paint);
+  Region invalidation4(tiling_rect());
+  UpdateAndExpandInvalidation(&invalidation4, tiling_size(), tiling_rect());
+  EXPECT_TRUE(pile_->IsSolidColor());
+  EXPECT_EQ(SK_ColorRED, pile_->GetSolidColor());
+
+  // but if we draw too many, we don't bother doing the analysis and we should
+  // no longer be in a solid state
+  client_.add_draw_rect(tiling_rect(), paint);
+  client_.add_draw_rect(tiling_rect(), paint);
+  client_.add_draw_rect(tiling_rect(), paint);
+  client_.add_draw_rect(tiling_rect(), paint);
+  client_.add_draw_rect(tiling_rect(), paint);
+  Region invalidation5(tiling_rect());
+  UpdateAndExpandInvalidation(&invalidation5, tiling_size(), tiling_rect());
+  EXPECT_FALSE(pile_->IsSolidColor());
+}
+
 }  // namespace
 }  // namespace cc