Font size in DomDistiller prefs syncs with local scaling

components/test/data/dom_distiller/pinch_tester.js

Index: components/test/data/dom_distiller/pinch_tester.js
diff --git a/components/test/data/dom_distiller/pinch_tester.js b/components/test/data/dom_distiller/pinch_tester.js
index e2c1df505166790970b0a1003c4bfa1bbb11d8ed..537312b98567ccfbf38141d66e63c54d73410b64 100644
--- a/components/test/data/dom_distiller/pinch_tester.js
+++ b/components/test/data/dom_distiller/pinch_tester.js
@@ -369,6 +369,43 @@ var pinchtest = (function() {
     pincher.handleTouchCancel();
   }
 
+  function testFontScaling() {
+    pincher.reset();
+    useFontScaling(1.5);
+    assertClose(pincher.status().clampedScale, 1.5);
+
+    var t = new touch();
+
+    var oldState = pincher.status();

[nyquist, 2015/08/11 06:27:57]

Would it be possible to add a one line comment above each of these sections?

Something like:
- Start touch
- Pinch-in
- Verified scale is less

- clear state, and re-initialize

- Start touch
- Pinch-out
- Verified scale is more

But probably  with some better text, but something along those lines?

It would make it both simple to understand this test overall, and also to verify
each section.

[wychen, 2015/08/31 21:47:39]

Done.

+    t.addTouchPoint(100, 100);
+    pincher.handleTouchStart(t.events());
+    t.addTouchPoint(300, 300);
+    pincher.handleTouchStart(t.events());
+
+    t.updateTouchPoint(0, 150, 150);
+    t.updateTouchPoint(1, 250, 250);
+    pincher.handleTouchMove(t.events());
+    assertTrue(pincher.status().clampedScale < 0.9 * oldState.clampedScale);
+
+    pincher.handleTouchCancel();
+
+    useFontScaling(0.8);
+    assertClose(pincher.status().clampedScale, 0.8);
+
+    t = new touch();
+    oldState = pincher.status();
+    t.addTouchPoint(150, 150);
+    pincher.handleTouchStart(t.events());
+    t.addTouchPoint(250, 250);
+    pincher.handleTouchStart(t.events());
+
+    t.updateTouchPoint(0, 100, 100);
+    t.updateTouchPoint(1, 300, 300);
+    pincher.handleTouchMove(t.events());
+    assertTrue(pincher.status().clampedScale > 1.1 * oldState.clampedScale);
+    pincher.handleTouchCancel();
+  }
+
   return {
     run: function(){
       testZoomOut();
@@ -380,6 +417,7 @@ var pinchtest = (function() {
       testCancel();
       testSingularity();
       testMinSpan();
+      testFontScaling();
       pincher.reset();
 
       return {success: true};