Expose IsSolidColor and write units tests

cc/resources/picture_pile_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <map>
 #include <utility>
 
 #include "cc/resources/picture_pile.h"
 #include "cc/test/fake_content_layer_client.h"
 #include "cc/test/fake_rendering_stats_instrumentation.h"
@@ skipping 21 matching lines @@
   typedef PicturePile::PictureMapKey PictureMapKey;
   typedef PicturePile::PictureMap PictureMap;
 
  protected:
     virtual ~TestPicturePile() {}
 };
 
 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());
   }
 
   void SetTilingSize(const gfx::Size& tiling_size) {
     Region invalidation;
     gfx::Rect viewport_rect(tiling_size);
     UpdateAndExpandInvalidation(&invalidation, tiling_size, viewport_rect);
   }
 
   gfx::Size tiling_size() const { return pile_->tiling_size(); }
@@ skipping 937 matching lines @@
       TestPicturePile::PictureMap::iterator it = map.find(key);
       EXPECT_TRUE(it != map.end() && it->second.GetPicture());
     }
   }
 
   // No invalidation when shrinking.
   EXPECT_EQ(Region().ToString(), invalidation.ToString());
   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);

[vmpstr, 2014/08/20 16:12:00]

I only count 8 draw commands, the limit is 10. Did I miscount or is there some
other commands in there?

[hendrikw, 2014/08/20 20:46:55]

I've added a comment.

+  Region invalidation5(tiling_rect());
+  UpdateAndExpandInvalidation(&invalidation5, tiling_size(), tiling_rect());
+  EXPECT_FALSE(pile_->IsSolidColor());
+}
+
 }  // namespace
 }  // namespace cc