Fix bug in RRectF constructor and mojo unpacking

gfx::RRectF is a wrapper for SkRRect. SkRRect normalizes the corner
radii values if the sum of 2 corner radii is larger than the length of
the side between these two corners. This means that the constructor
cannot initialize a rounded rect by sequentially setting the corner
radius for each corner. All the corners have to be set atomically using
the API provided by SkRRect so that the normalization happens correctly.

Bug: 966488
Change-Id: I0e3f373e4425af905f1be1fc1bc9fda983bdf600
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1629010Reviewed-by: Mason Freed <masonfreed@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Malay Keshav <malaykeshav@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664000}

ui/gfx/mojo/rrect_f_struct_traits.h

@@ -89,9 +89,10 @@ struct StructTraits<gfx::mojom::RRectFDataView, gfx::RRectF> {
     gfx::Vector2dF upper_left;
     if (!data.ReadUpperLeft(&upper_left))
       return false;
-    *out = gfx::RRectF(rect, upper_left.x(), upper_left.y());
-    if (type <= gfx::RRectF::Type::kSimple)
+    if (type <= gfx::RRectF::Type::kSimple) {
+      *out = gfx::RRectF(rect, upper_left.x(), upper_left.y());
       return true;
+    }
     gfx::Vector2dF upper_right;
     gfx::Vector2dF lower_right;
     gfx::Vector2dF lower_left;
@@ -100,9 +101,9 @@ struct StructTraits<gfx::mojom::RRectFDataView, gfx::RRectF> {
         !data.ReadLowerLeft(&lower_left)) {
       return false;
     }
-    out->SetCornerRadii(gfx::RRectF::Corner::kUpperRight, upper_right);
-    out->SetCornerRadii(gfx::RRectF::Corner::kLowerRight, lower_right);
-    out->SetCornerRadii(gfx::RRectF::Corner::kLowerLeft, lower_left);
+    *out = gfx::RRectF(rect, upper_left.x(), upper_left.y(), upper_right.x(),
+                       upper_right.y(), lower_right.x(), lower_right.y(),
+                       lower_left.x(), lower_left.y());
     return true;
   }
 };

ui/gfx/mojo/struct_traits_unittest.cc

@@ -273,6 +273,12 @@ TEST_F(StructTraitsTest, RRectF) {
   EXPECT_EQ(input.GetType(), RRectF::Type::kOval);
   proxy->EchoRRectF(input, &output);
   EXPECT_EQ(input, output);
+  input.SetCornerRadii(RRectF::Corner::kUpperLeft, 50, 50);
+  input.SetCornerRadii(RRectF::Corner::kUpperRight, 20, 20);
+  input.SetCornerRadii(RRectF::Corner::kLowerRight, 0, 0);
+  input.SetCornerRadii(RRectF::Corner::kLowerLeft, 0, 0);
+  proxy->EchoRRectF(input, &output);
+  EXPECT_EQ(input, output);
 }
 
 }  // namespace gfx

ui/gfx/rrect_f.cc

@@ -42,11 +42,19 @@ RRectF::RRectF(float x,
                float lower_right_x,
                float lower_right_y,
                float lower_left_x,
-               float lower_left_y)
-    : RRectF(x, y, width, height, upper_left_x, upper_left_y) {
-  SetCornerRadii(RRectF::Corner::kUpperRight, upper_right_x, upper_right_y);
-  SetCornerRadii(RRectF::Corner::kLowerRight, lower_right_x, lower_right_y);
-  SetCornerRadii(RRectF::Corner::kLowerLeft, lower_left_x, lower_left_y);
+               float lower_left_y) {
+  SkVector radii[4] = {
+      {upper_left_x, upper_left_y},
+      {upper_right_x, upper_right_y},
+      {lower_right_x, lower_right_y},
+      {lower_left_x, lower_left_y},
+  };
+  skrrect_.setRectRadii(SkRect::MakeXYWH(x, y, width, height), radii);
+  if (IsEmpty()) {
+    // Make sure that empty rects are created fully empty, not with some
+    // non-zero dimensions.
+    skrrect_ = SkRRect::MakeEmpty();
+  }
 }
 
 gfx::Vector2dF RRectF::GetSimpleRadii() const {