Ensure text metric calculation always uses the text cache

These locations outside of `Text` were calling
`Renderer.get_text_width_height_descent` directly which meant that
1. they were not cached, and 2. the `text_placeholders` fixture did not
catch their use.

Fortunately, this only affected one test figure.

Author: QuLogic

lib/matplotlib/offsetbox.py

@@ -794,9 +794,10 @@ def get_offset(self):
         return self._offset
 
     def get_bbox(self, renderer):
-        _, h_, d_ = renderer.get_text_width_height_descent(
-            "lp", self._text._fontproperties,
-            ismath="TeX" if self._text.get_usetex() else False)
+        _, h_, d_ = mtext._get_text_metrics_with_cache(
+            renderer, "lp", self._text._fontproperties,
+            ismath="TeX" if self._text.get_usetex() else False,
+            dpi=self.get_figure(root=True).dpi)
 
         bbox, info, yd = self._text._get_layout(renderer)
         w, h = bbox.size

lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout10.png

@@ -694,10 +694,10 @@ def _get_rendered_text_width(self, text):
         Return the width of a given text string, in pixels.
         """
 
-        w, h, d = self._renderer.get_text_width_height_descent(
-            text,
-            self.get_fontproperties(),
-            cbook.is_math_text(text))
+        w, h, d = _get_text_metrics_with_cache(
+            self._renderer, text, self.get_fontproperties(),
+            cbook.is_math_text(text),
+            self.get_figure(root=True).dpi)
         return math.ceil(w)
 
     def _get_wrapped_text(self):

lib/matplotlib/text.py

@@ -588,8 +588,9 @@ def get_texts_widths_heights_descents(self, renderer):
             if not label.strip():
                 continue
             clean_line, ismath = self._preprocess_math(label)
-            whd = renderer.get_text_width_height_descent(
-                clean_line, self._fontproperties, ismath=ismath)
+            whd = mtext._get_text_metrics_with_cache(
+                renderer, clean_line, self._fontproperties, ismath=ismath,
+                dpi=self.get_figure(root=True).dpi)
             whd_list.append(whd)
         return whd_list