Make sure CI breaks, as this is a bug.

Author: matanlurey

shell/platform/android/surface_texture_external_texture.cc

@@ -57,11 +57,17 @@ void SurfaceTextureExternalTexture::Paint(PaintContext& context,
   if (dl_image_) {
     DlAutoCanvasRestore autoRestore(context.canvas, true);
 
-    // The incoming texture is vertically flipped, so we flip it
-    // back. OpenGL's coordinate system has Positive Y equivalent to up, while
-    // Skia's coordinate system has Negative Y equvalent to up.
-    context.canvas->Translate(bounds.x(), bounds.y() + bounds.height());
-    context.canvas->Scale(bounds.width(), -bounds.height());
+    // The incoming texture is vertically flipped, so we flip it back.
+    //
+    // OpenGL's coordinate system has Positive Y equivalent to up, while Skia's
+    // coordinate system (as well as Impeller's) has Negative Y equvalent to up.
+    {
+      // Move (translate) the origin to the bottom-left corner of the image.
+      context.canvas->Translate(bounds.x(), bounds.y() + bounds.height());
+
+      // No change in the X axis, but we need to flip the Y axis.
+      context.canvas->Scale(1, -1);
+    }
 
     if (!transform_.isIdentity()) {
       DlImageColorSource source(dl_image_, DlTileMode::kClamp,
@@ -72,7 +78,8 @@ void SurfaceTextureExternalTexture::Paint(PaintContext& context,
         paintWithShader = *context.paint;
       }
       paintWithShader.setColorSource(&source);
-      context.canvas->DrawRect(SkRect::MakeWH(1, 1), paintWithShader);
+      context.canvas->DrawRect(SkRect::MakeWH(bounds.width(), bounds.height()),
+                               paintWithShader);
     } else {
       context.canvas->DrawImage(dl_image_, {0, 0}, sampling, context.paint);
     }