[flow] fix RasterCache to round out device bounds

With fractional coordinates, it's not enough to round up device bounds
width and height. Round out to get a large enough integer-size texture.

Fixes: flutter/flutter#107733
Fixes: flutter/flutter#107921
Fixes: flutter/flutter#109608

flow/raster_cache.cc

@@ -34,16 +34,16 @@ void RasterCacheResult::draw(SkCanvas& canvas, const SkPaint* paint) const {
 
   SkRect bounds =
       RasterCacheUtil::GetDeviceBounds(logical_rect_, canvas.getTotalMatrix());
+  bounds.roundOut(&bounds);
 #ifndef NDEBUG
   // The image dimensions should always be larger than the device bounds and
   // smaller than the device bounds plus one pixel, at the same time, we must
   // introduce epsilon to solve the round-off error. The value of epsilon is
   // 1/512, which represents half of an AA sample.
   float epsilon = 1 / 512.0;
-  FML_DCHECK(image_->dimensions().width() - bounds.width() > -epsilon &&
-             image_->dimensions().height() - bounds.height() > -epsilon &&
-             image_->dimensions().width() - bounds.width() < 1 + epsilon &&
-             image_->dimensions().height() - bounds.height() < 1 + epsilon);
+  FML_DCHECK(
+      std::abs(bounds.width() - image_->dimensions().width()) <= 1 + epsilon &&
+      std::abs(bounds.height() - image_->dimensions().height()) <= 1 + epsilon);
 #endif
   canvas.resetMatrix();
   flow_.Step();
@@ -65,11 +65,13 @@ std::unique_ptr<RasterCacheResult> RasterCache::Rasterize(
     const {
   TRACE_EVENT0("flutter", "RasterCachePopulate");
 
-  SkRect dest_rect =
+  SkRect bounds =
       RasterCacheUtil::GetDeviceBounds(context.logical_rect, context.matrix);
   // we always round out here so that the texture is integer sized.
-  int width = SkScalarCeilToInt(dest_rect.width());
-  int height = SkScalarCeilToInt(dest_rect.height());
+  SkIRect dest_rect;
+  bounds.roundOut(&dest_rect);
+  int width = dest_rect.width();
+  int height = dest_rect.height();
 
   const SkImageInfo image_info = SkImageInfo::MakeN32Premul(
       width, height, sk_ref_sp(context.dst_color_space));

flow/raster_cache_unittests.cc

@@ -454,6 +454,35 @@ TEST(RasterCache, DeviceRectRoundOutForDisplayList) {
   ASSERT_TRUE(display_list_item.Draw(paint_context, &canvas, &paint));
 }
 
+TEST(RasterCache, DeviceRectRoundOutRasterize) {
+  flutter::RasterCache cache(1);
+  FixedRefreshRateStopwatch raster_time;
+  FixedRefreshRateStopwatch ui_time;
+  PaintContextHolder paint_context_holder =
+      GetSamplePaintContextHolder(&cache, &raster_time, &ui_time);
+  auto& paint_context = paint_context_holder.paint_context;
+  int surface_width = -1;
+  int surface_height = -1;
+  auto dummy_draw_function = [&](SkCanvas* canvas) {
+    SkSurface* surface = canvas->getSurface();
+    surface_width = surface->width();
+    surface_height = surface->height();
+  };
+  RasterCache::Context r_context = {
+      // clang-format off
+        .gr_context         = paint_context.gr_context,
+        .dst_color_space    = paint_context.dst_color_space,
+        .matrix             = SkMatrix::I(),
+        .logical_rect       = SkRect::MakeLTRB(-52.1, -19.5, 878.6, 457.5),
+        .flow_type          = "RasterCacheFlow::DisplayList",
+      // clang-format on
+  };
+
+  cache.Rasterize(r_context, dummy_draw_function, nullptr);
+  ASSERT_EQ(surface_width, 932);
+  ASSERT_EQ(surface_height, 478);
+}
+
 TEST(RasterCache, NestedOpCountMetricUsedForDisplayList) {
   size_t threshold = 1;
   flutter::RasterCache cache(threshold);