Bug 1288938: Allow passing different reasons to dirty a non display SVG text frame. r=heycam

Otherwise, when a glyph changes, we might end up doing too much work, destroying
the text-run and the observer that dirtied the frame, causing an assertion when
trying to delete it from the observer set.

MozReview-Commit-ID: LMQVr6pYFVM

layout/generic/nsFrame.cpp

@@ -843,7 +843,7 @@ nsFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
     if (anonBlock && !(anonBlock->GetStateBits() & NS_FRAME_FIRST_REFLOW) &&
         (svgTextFrame->GetStateBits() & NS_FRAME_IS_NONDISPLAY) &&
         !(svgTextFrame->GetStateBits() & NS_STATE_SVG_TEXT_IN_REFLOW)) {
-      svgTextFrame->ScheduleReflowSVGNonDisplayText();
+      svgTextFrame->ScheduleReflowSVGNonDisplayText(nsIPresShell::eStyleChange);
     }
   }
 

layout/generic/nsTextFrame.cpp

@@ -655,7 +655,7 @@ InvalidateFrameDueToGlyphsChanged(nsIFrame* aFrame)
       auto svgTextFrame = static_cast<SVGTextFrame*>(
                             nsLayoutUtils::GetClosestFrameOfType(f,
                             nsGkAtoms::svgTextFrame));
-      svgTextFrame->ScheduleReflowSVGNonDisplayText();
+      svgTextFrame->ScheduleReflowSVGNonDisplayText(nsIPresShell::eResize);
     } else {
       // Theoretically we could just update overflow areas, perhaps using
       // OverflowChangedTracker, but that would do a bunch of work eagerly that

layout/svg/SVGTextFrame.cpp

@@ -3322,7 +3322,7 @@ SVGTextFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
     // child to be reflowed when it is next painted, and (b) not cause the
     // <text> to be repainted anyway since the user of the <mask> would not
     // know it needs to be repainted.
-    ScheduleReflowSVGNonDisplayText();
+    ScheduleReflowSVGNonDisplayText(nsIPresShell::eStyleChange);
   }
 }
 
@@ -3356,7 +3356,7 @@ SVGTextFrame::ReflowSVGNonDisplayText()
 }
 
 void
-SVGTextFrame::ScheduleReflowSVGNonDisplayText()
+SVGTextFrame::ScheduleReflowSVGNonDisplayText(nsIPresShell::IntrinsicDirty aReason)
 {
   MOZ_ASSERT(!nsSVGUtils::OuterSVGIsCallingReflowSVG(this),
              "do not call ScheduleReflowSVGNonDisplayText when the outer SVG "
@@ -3394,8 +3394,7 @@ SVGTextFrame::ScheduleReflowSVGNonDisplayText()
 
   MOZ_ASSERT(f, "should have found an ancestor frame to reflow");
 
-  PresContext()->PresShell()->FrameNeedsReflow(
-    f, nsIPresShell::eStyleChange, NS_FRAME_IS_DIRTY);
+  PresContext()->PresShell()->FrameNeedsReflow(f, aReason, NS_FRAME_IS_DIRTY);
 }
 
 NS_IMPL_ISUPPORTS(SVGTextFrame::MutationObserver, nsIMutationObserver)
@@ -5296,7 +5295,7 @@ void
 SVGTextFrame::ScheduleReflowSVG()
 {
   if (mState & NS_FRAME_IS_NONDISPLAY) {
-    ScheduleReflowSVGNonDisplayText();
+    ScheduleReflowSVGNonDisplayText(nsIPresShell::eStyleChange);
   } else {
     nsSVGUtils::ScheduleReflowSVG(this);
   }

layout/svg/SVGTextFrame.h

@@ -399,11 +399,13 @@ public:
    * nsSVGDisplayContainerFrame::ReflowSVG will call ReflowSVGNonDisplayText on
    * it.
    *
-   * The only case where we have to do this is in response to a style change on
-   * a non-display <text>. It is done in response to glyphs changes on
-   * non-display <text> (i.e., animated SVG-in-OpenType glyphs).
+   * We have to do this in two cases: in response to a style change on a
+   * non-display <text>, where aReason will be eStyleChange (the common case),
+   * and also in response to glyphs changes on non-display <text> (i.e.,
+   * animated SVG-in-OpenType glyphs), in which case aReason will be eResize,
+   * since layout doesn't need to be recomputed.
    */
-  void ScheduleReflowSVGNonDisplayText();
+  void ScheduleReflowSVGNonDisplayText(nsIPresShell::IntrinsicDirty aReason);
 
   /**
    * Updates the mFontSizeScaleFactor value by looking at the range of