Backed out changeset d6e7f810f7d3 (bug 1424878)for failing reftests related to usercss/usercss-uppercase.html a=backout on a CLOSED TREE

layout/base/nsPresContext.cpp

@@ -735,11 +735,14 @@ nsPresContext::AppUnitsPerDevPixelChanged()
     mDeviceContext->FlushFontCache();
   }
 
-  MediaFeatureValuesChanged({
-    eRestyle_ForceDescendants,
-    NS_STYLE_HINT_REFLOW,
-    MediaFeatureChangeReason::ResolutionChange
-  });
+  if (HasCachedStyleData()) {
+    // All cached style data must be recomputed.
+    MediaFeatureValuesChanged({
+      eRestyle_ForceDescendants,
+      NS_STYLE_HINT_REFLOW,
+      MediaFeatureChangeReason::ResolutionChange
+    });
+  }
 
   mCurAppUnitsPerDevPixel = AppUnitsPerDevPixel();
 }
@@ -1403,13 +1406,18 @@ nsPresContext::UpdateEffectiveTextZoom()
 
   mEffectiveTextZoom = newZoom;
 
-  // Media queries could have changed, since we changed the meaning
-  // of 'em' units in them.
-  MediaFeatureValuesChanged({
-    eRestyle_ForceDescendants,
-    NS_STYLE_HINT_REFLOW,
-    MediaFeatureChangeReason::ZoomChange
-  });
+  // In case of servo, stylist.device might have already generated the default
+  // computed values with the previous effective text zoom value even if the
+  // pres shell has not initialized yet.
+  if (mDocument->IsStyledByServo() || HasCachedStyleData()) {
+    // Media queries could have changed, since we changed the meaning
+    // of 'em' units in them.
+    MediaFeatureValuesChanged({
+      eRestyle_ForceDescendants,
+      NS_STYLE_HINT_REFLOW,
+      MediaFeatureChangeReason::ZoomChange
+    });
+  }
 }
 
 float
@@ -1452,12 +1460,13 @@ nsPresContext::SetOverrideDPPX(float aDPPX)
   // SetOverrideDPPX is called during navigations, including history
   // traversals.  In that case, it's typically called with our current value,
   // and we don't need to actually do anything.
-  if (aDPPX == mOverrideDPPX) {
-    return;
-  }
+  if (aDPPX != mOverrideDPPX) {
+    mOverrideDPPX = aDPPX;
 
-  mOverrideDPPX = aDPPX;
-  MediaFeatureValuesChanged({ MediaFeatureChangeReason::ResolutionChange });
+    if (HasCachedStyleData()) {
+      MediaFeatureValuesChanged({ MediaFeatureChangeReason::ResolutionChange });
+    }
+  }
 }
 
 gfxSize
@@ -2201,6 +2210,10 @@ NotifyTabSizeModeChanged(TabParent* aTab, void* aArg)
 void
 nsPresContext::SizeModeChanged(nsSizeMode aSizeMode)
 {
+  if (!HasCachedStyleData()) {
+    return;
+  }
+
   nsContentUtils::CallOnAllRemoteChildren(mDocument->GetWindow(),
                                           NotifyTabSizeModeChanged,
                                           &aSizeMode);
@@ -2773,6 +2786,27 @@ nsPresContext::NotifyDidPaintForSubtree(uint64_t aTransactionId,
   mDocument->EnumerateSubDocuments(nsPresContext::NotifyDidPaintSubdocumentCallback, &closure);
 }
 
+bool
+nsPresContext::HasCachedStyleData()
+{
+  if (!mShell) {
+    return false;
+  }
+
+  if (mShell->StyleSet()->IsGecko()) {
+#ifdef MOZ_OLD_STYLE
+    return mShell->StyleSet()->AsGecko()->HasCachedStyleData();
+#else
+    MOZ_CRASH("old style system disabled");
+#endif
+  }
+
+  // XXXheycam ServoStyleSets do not use the rule tree, so just assume for now
+  // that we need to restyle when e.g. dppx changes assuming we're sufficiently
+  // bootstrapped.
+  return mShell->DidInitialize();
+}
+
 already_AddRefed<nsITimer>
 nsPresContext::CreateTimer(nsTimerCallbackFunc aCallback,
                            const char* aName,

layout/base/nsPresContext.h

@@ -472,7 +472,7 @@ public:
     if (!r.IsEqualEdges(mVisibleArea)) {
       mVisibleArea = r;
       // Visible area does not affect media queries when paginated.
-      if (!IsPaginated()) {
+      if (!IsPaginated() && HasCachedStyleData()) {
         MediaFeatureValuesChanged({
           mozilla::MediaFeatureChangeReason::ViewportChange
         });
@@ -619,19 +619,19 @@ public:
    * independent of the language-specific global preference.
    */
   void SetBaseMinFontSize(int32_t aMinFontSize) {
-    if (aMinFontSize == mBaseMinFontSize) {
+    if (aMinFontSize == mBaseMinFontSize)
       return;
-    }
 
     mBaseMinFontSize = aMinFontSize;
-
-    // Media queries could have changed, since we changed the meaning
-    // of 'em' units in them.
-    MediaFeatureValuesChanged({
-      eRestyle_ForceDescendants,
-      NS_STYLE_HINT_REFLOW,
-      mozilla::MediaFeatureChangeReason::MinFontSizeChange
-    });
+    if (HasCachedStyleData()) {
+      // Media queries could have changed, since we changed the meaning
+      // of 'em' units in them.
+      MediaFeatureValuesChanged({
+        eRestyle_ForceDescendants,
+        NS_STYLE_HINT_REFLOW,
+        mozilla::MediaFeatureChangeReason::MinFontSizeChange
+      });
+    }
   }
 
   float GetFullZoom() { return mFullZoom; }
@@ -1282,6 +1282,9 @@ protected:
 
   bool HavePendingInputEvent();
 
+  // Can't be inline because we can't include nsStyleSet.h.
+  bool HasCachedStyleData();
+
   // Creates a one-shot timer with the given aCallback & aDelay.
   // Returns a refcounted pointer to the timer (or nullptr on failure).
   already_AddRefed<nsITimer> CreateTimer(nsTimerCallbackFunc aCallback,

layout/style/nsStyleSet.h

@@ -475,6 +475,16 @@ class nsStyleSet final
     --mRootStyleContextCount;
   }
 
+  // Return whether the rule tree has cached data such that we need to
+  // do dynamic change handling for changes that change the results of
+  // media queries or require rebuilding all style data.
+  // We don't care whether we have cached rule processors or whether
+  // they have cached rule cascades; getting the rule cascades again in
+  // order to do rule matching will get the correct rule cascade.
+  bool HasCachedStyleData() const {
+    return (mRuleTree && mRuleTree->TreeHasCachedData()) || mRootStyleContextCount > 0;
+  }
+
   // Notify the style set that a rulenode is no longer in use, or was
   // just created and is not in use yet.
   static const uint32_t kGCInterval = 300;

testing/web-platform/meta/MANIFEST.json

@@ -160077,18 +160077,6 @@
      {}
     ]
    ],
-   "css/mediaqueries/viewport-script-dynamic.html": [
-    [
-     "/css/mediaqueries/viewport-script-dynamic.html",
-     [
-      [
-       "/css/mediaqueries/viewport-script-dynamic-ref.html",
-       "=="
-      ]
-     ],
-     {}
-    ]
-   ],
    "css/motion/offset-anchor-transform-box-fill-box.html": [
     [
      "/css/motion/offset-anchor-transform-box-fill-box.html",
@@ -260047,11 +260035,6 @@
      {}
     ]
    ],
-   "css/mediaqueries/viewport-script-dynamic-ref.html": [
-    [
-     {}
-    ]
-   ],
    "css/motion/animation/resources/interpolation-testcommon.js": [
     [
      {}
@@ -526237,14 +526220,6 @@
    "234627714b5f304ad7efbeaf2dea3455125f8cc4",
    "testharness"
   ],
-  "css/mediaqueries/viewport-script-dynamic-ref.html": [
-   "7d55c513e2de39c9b362fc864233a3008ca6ced2",
-   "support"
-  ],
-  "css/mediaqueries/viewport-script-dynamic.html": [
-   "1c2ba1a9116942599804ed29553e85628afadb04",
-   "reftest"
-  ],
   "css/motion/animation/offset-anchor-interpolation.html": [
    "30eb3ea68aa502d93125d4e54ff15c0a96458cfa",
    "testharness"
@@ -592274,19 +592249,19 @@
    "wdspec"
   ],
   "webdriver/tests/actions/modifier_click.py": [
-   "88a384182fdd9df1515b9d8cfda8f56aed138ec7",
+   "56df38086ef05cd8bff1437038efb598ab63f1e3",
    "wdspec"
   ],
   "webdriver/tests/actions/mouse.py": [
-   "edad7693fcd01b418821942edb870191db64ea41",
+   "2fb4c47335f144a2dd6f16db4c20239116f20fed",
    "wdspec"
   ],
   "webdriver/tests/actions/mouse_dblclick.py": [
-   "f6afcb8c0fa017d58a9fcdd3cc474e0c8fd52db5",
+   "932b053eef5e052d53ab2007540428d68b758ad4",
    "wdspec"
   ],
   "webdriver/tests/actions/pointer_origin.py": [
-   "a9a99d58daec7719ee53ed758f566ccceb582f65",
+   "da2a9f21018582c8cd52d206d172841f71fd19f3",
    "wdspec"
   ],
   "webdriver/tests/actions/sequence.py": [
@@ -592306,7 +592281,7 @@
    "support"
   ],
   "webdriver/tests/actions/support/mouse.py": [
-   "bc7da107e5b897105dfa7405aa57cba7355854dc",
+   "208a1c4fbc0d5c542d17de7f6474d477ce1feb45",
    "support"
   ],
   "webdriver/tests/actions/support/refine.py": [
@@ -592314,7 +592289,7 @@
    "support"
   ],
   "webdriver/tests/actions/support/test_actions_wdspec.html": [
-   "95203777fcc012ab64465287737a89a4ba2c31dc",
+   "34f99c46ac9c52e5902477c26a3d16a89a29235a",
    "support"
   ],
   "webdriver/tests/conftest.py": [

testing/web-platform/meta/css/mediaqueries/viewport-script-dynamic.html.ini

@@ -1,2 +0,0 @@
-[viewport-script-dynamic.html]
-  prefs: [dom.meta-viewport.enabled:true]

testing/web-platform/tests/css/mediaqueries/viewport-script-dynamic-ref.html

@@ -1,9 +0,0 @@
-<!doctype html>
-<meta charset="utf-8">
-<title>CSS Test Reference</title>
-<link rel="author" href="mailto:emilio@crisal.io">
-<meta name="viewport" content="width=300">
-<style>
-p { color: green; }
-</style>
-<p>Should be green</p>

testing/web-platform/tests/css/mediaqueries/viewport-script-dynamic.html

@@ -1,20 +0,0 @@
-<!doctype html>
-<meta charset="utf-8">
-<title>CSS Test: Meta viewport after a script and stylesheets</title>
-<link rel="author" href="mailto:emilio@crisal.io">
-<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1424878">
-<link rel="help" href="https://drafts.csswg.org/mediaqueries/#mf-dimensions">
-<link rel="match" href="viewport-script-dynamic-ref.html">
-<style>
-p { color: green; }
-/* Ensure that we initially match it, and stop matching it afterwards */
-@media (min-width: 310px) {
-  p {
-    color: red;
-  }
-}
-</style>
-<!-- The broken script below is the point of the test, see the bugzilla bug. -->
-<script src="intentionally-broken-url.js"></script>
-<meta name="viewport" content="width=300">
-<p>Should be green</p>