Add ASSERTs in BidiResolver and RenderBlockLineLayout

Source/core/rendering/RenderBlockLineLayout.cpp

Index: Source/core/rendering/RenderBlockLineLayout.cpp
diff --git a/Source/core/rendering/RenderBlockLineLayout.cpp b/Source/core/rendering/RenderBlockLineLayout.cpp
index 2ea53d52e3143a879b24e9be433d973d7a95d2a0..5e6610464f0f164845c68949cb4b57a532d67726 100644
--- a/Source/core/rendering/RenderBlockLineLayout.cpp
+++ b/Source/core/rendering/RenderBlockLineLayout.cpp
@@ -1302,10 +1302,7 @@ static inline void constructBidiRunsForSegment(InlineBidiResolver& topResolver,
         // rniwa says previousLineBrokeCleanly is just a WinIE hack and could always be false here?
         isolatedResolver.createBidiRunsForLine(endOfRuns, NoVisualOverride, previousLineBrokeCleanly);
 
-        // Note that we do not delete the runs from the resolver.
-        // We're not guaranteed to get any BidiRuns in the previous step. If we don't, we allow the placeholder
-        // itself to be turned into an InlineBox. We can't remove it here without potentially losing track of
-        // the logically last run.
+        ASSERT(isolatedResolver.runs().runCount());
         if (isolatedResolver.runs().runCount())
             bidiRuns.replaceRunWithRuns(isolatedRun, isolatedResolver.runs());