Fix Text layout cache lookup.

Even though `Text._get_layout` takes a `renderer` parameter, the cache is looked up by the `self._renderer` attribute. If an alternate renderer is provided without changing any other properties, the cached layout from the previous renderer is returned. An alternate renderer is passed by `offsetbox.TextArea`, which, through its use in legends, causes the legend to shift slightly if figures are saved in different formats. Fixes #6899.
matplotlib · efiring · Nov 8, 2016 · Nov 7, 2016 · Nov 7, 2016 · 8627dbd50e5fb6383a7cf8cf10cdf4f08f1af1d2
commit 8627dbd50e5fb6383a7cf8cf10cdf4f08f1af1d2
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/hist_stacked_bar.svg b/lib/matplotlib/tests/baseline_images/test_axes/hist_stacked_bar.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/markevery.svg b/lib/matplotlib/tests/baseline_images/test_axes/markevery.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/markevery_line.svg b/lib/matplotlib/tests/baseline_images/test_axes/markevery_line.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_legend/fancy.svg b/lib/matplotlib/tests/baseline_images/test_legend/fancy.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_legend/framealpha.svg b/lib/matplotlib/tests/baseline_images/test_legend/framealpha.svg