Don't use @media with feature expressions in UA style.

We don't support MediaValues based feature evaluation in UA stylesheet,
only matching media types. There was an instance of
(-webkit-min-device-pixel-ratio: 2) in mediaControls.css which would
always evaluate to true in the UA sheet, but not in the context of the
evaluator in the StyleEngine for dpr=1. That caused us to constantly
update active stylesheets for frame resizes because we thought the media
result would change.

This also contributed to hide a bug on tweetdeck.twitter.com before we
optimized the ruleset invalidation for media query changes.

This should not be a behavior change for the mediaControls stylesheet
since the removed query would always evaluate to true so that we would
always use the high resolution image.

Bug: 1088340
Change-Id: I23f582893b21db6f14903836d58608caa82e5577
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2228848Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#775144}

third_party/blink/renderer/core/css/media_query_evaluator.cc

@@ -910,8 +910,13 @@ void MediaQueryEvaluator::Init() {
 }
 
 bool MediaQueryEvaluator::Eval(const MediaQueryExp& expr) const {
-  if (!media_values_ || !media_values_->HasValues())
-    return true;
+  if (!media_values_ || !media_values_->HasValues()) {
+    // media_values_ should only be nullptr when parsing UA stylesheets. The
+    // only media queries we support in UA stylesheets are media type queries.
+    // If HasValues() return false, it means the document frame is nullptr.
+    NOTREACHED();
+    return false;
+  }
 
   DCHECK(g_function_map);
 

third_party/blink/renderer/core/css/media_query_evaluator.h

@@ -62,9 +62,9 @@ class CORE_EXPORT MediaQueryEvaluator final
 
   MediaQueryEvaluator() = delete;
 
-  // Creates evaluator which evaluates only simple media queries
-  // Evaluator returns true for acceptedMediaType and returns true for any media
-  // features.
+  // Creates evaluator to evaluate media types only. Evaluator returns true for
+  // accepted_media_type and triggers a NOTREACHED returning false for any media
+  // features. Should only be used for UA stylesheets.
   MediaQueryEvaluator(const char* accepted_media_type);
 
   // Creates evaluator which evaluates full media queries.

third_party/blink/renderer/core/css/style_engine_test.cc

@@ -2732,6 +2732,12 @@ TEST_F(StyleEngineTest, AtPropertyUseCount) {
   EXPECT_TRUE(GetDocument().IsUseCounted(WebFeature::kCSSAtRuleProperty));
 }
 
+TEST_F(StyleEngineTest, MediaQueryAffectedByViewportSanityCheck) {
+  GetDocument().body()->setInnerHTML("<audio controls>");
+  UpdateAllLifecyclePhases();
+  EXPECT_FALSE(GetStyleEngine().MediaQueryAffectedByViewportChange());
+}
+
 class ParameterizedStyleEngineTest
     : public testing::WithParamInterface<bool>,
       private ScopedCSSReducedFontLoadingInvalidationsForTest,

third_party/blink/renderer/modules/media_controls/resources/mediaControls.css

@@ -1365,8 +1365,8 @@ video::-webkit-media-controls.immersive-mode div[pseudo="-webkit-media-controls-
 
   /* Taller scrim. */
   background:
-    -webkit-image-set(url('default_100_percent/vr_gradient_bg.png') 1x)
-    repeat-x bottom left;
+    -webkit-image-set(url('default_200_percent/vr_gradient_bg.png') 1x)
+    repeat-x bottom left auto 198px;
 }
 
 video::-webkit-media-controls.immersive-mode input[pseudo="-webkit-media-controls-timeline" i]::-internal-track-segment-highlight-before,
@@ -1446,14 +1446,6 @@ video::-webkit-media-controls.immersive-mode input[pseudo="-internal-media-contr
   display: none;
 }
 
-@media (-webkit-min-device-pixel-ratio: 2) {
-  video::-webkit-media-controls.immersive-mode div[pseudo="-webkit-media-controls-panel" i] {
-    background:
-      -webkit-image-set(url('default_200_percent/vr_gradient_bg.png') 1x)
-      repeat-x bottom left auto 198px;
-  }
-}
-
 /**
  * Test mode styles to remove animations/transitions to make web tests
  * simpler.