Material PDF: Improve layout of PDF viewer in very small windows

chrome/browser/resources/pdf/index-material.css

Index: chrome/browser/resources/pdf/index-material.css
diff --git a/chrome/browser/resources/pdf/index-material.css b/chrome/browser/resources/pdf/index-material.css
index 1e9df5e53761d27d2b4671f977f4dac0e04b4186..a443bac50ec688cf857b1bd5e19251dc83b72efc 100644
--- a/chrome/browser/resources/pdf/index-material.css
+++ b/chrome/browser/resources/pdf/index-material.css
@@ -30,3 +30,21 @@ viewer-pdf-toolbar {
   position: absolute;
   z-index: 0;
 }
+
+@media(max-height: 250px) {
+  viewer-pdf-toolbar {
+    display: none;
+  }
+}
+
+@media(max-height: 200px) {
+  viewer-zoom-toolbar {
+    display: none;
+  }
+}
+
+@media(max-width: 300px) {
+  viewer-zoom-toolbar {
+    display: none;
+  }
+}