Add more checks to diagnose MediaQuerySet issue

third_party/WebKit/Source/core/css/MediaList.cpp

Index: third_party/WebKit/Source/core/css/MediaList.cpp
diff --git a/third_party/WebKit/Source/core/css/MediaList.cpp b/third_party/WebKit/Source/core/css/MediaList.cpp
index 521ab14c4a853a4ee7d927a6284f08c42643fe8a..ee1d1464db63c8864269332977cda2288352e6be 100644
--- a/third_party/WebKit/Source/core/css/MediaList.cpp
+++ b/third_party/WebKit/Source/core/css/MediaList.cpp
@@ -67,11 +67,10 @@ MediaQuerySet* MediaQuerySet::Create(const String& media_string) {
 
 bool MediaQuerySet::Set(const String& media_string) {
   MediaQuerySet* result = Create(media_string);
-#if DCHECK_IS_ON()
+  // TODO(keishi) Changed DCHECK to CHECK for crbug.com/699269 diagnosis
   for (const auto& query : result->queries_) {
-    DCHECK(query);
+    CHECK(query);
   }
-#endif
   queries_.Swap(result->queries_);
   return true;
 }
@@ -87,7 +86,8 @@ bool MediaQuerySet::Add(const String& query_string) {
     return true;
 
   MediaQuery* new_query = result->queries_[0].Release();
-  DCHECK(new_query);
+  // TODO(keishi) Changed DCHECK to CHECK for crbug.com/699269 diagnosis
+  CHECK(new_query);
 
   // If comparing with any of the media queries in the collection of media
   // queries returns true terminate these steps.
@@ -112,7 +112,8 @@ bool MediaQuerySet::Remove(const String& query_string_to_remove) {
     return true;
 
   MediaQuery* new_query = result->queries_[0].Release();
-  DCHECK(new_query);
+  // TODO(keishi) Changed DCHECK to CHECK for crbug.com/699269 diagnosis
+  CHECK(new_query);
 
   // Remove any media query from the collection of media queries for which
   // comparing with the media query returns true.
@@ -130,7 +131,8 @@ bool MediaQuerySet::Remove(const String& query_string_to_remove) {
 }
 
 void MediaQuerySet::AddMediaQuery(MediaQuery* media_query) {
-  DCHECK(media_query);
+  // TODO(keishi) Changed DCHECK to CHECK for crbug.com/699269 diagnosis
+  CHECK(media_query);
   queries_.push_back(media_query);
 }
 
@@ -209,12 +211,11 @@ void MediaList::appendMedium(const String& medium,
 }
 
 void MediaList::Reattach(MediaQuerySet* media_queries) {
-  DCHECK(media_queries);
-#if DCHECK_IS_ON
-  for (const auto& query : mediaQueries->queryVector) {
-    DCHECK(query);
+  // TODO(keishi) Changed DCHECK to CHECK for crbug.com/699269 diagnosis
+  CHECK(media_queries);
+  for (const auto& query : media_queries->QueryVector()) {
+    CHECK(query);
   }
-#endif
   media_queries_ = media_queries;
 }