Turn a DCHECK() into a CHECK() in WebLocalFrameImpl.

Turn |blink::WebLocalFrameImpl::is_in_printing_| from a variable only
used for DCHECKs into one that is always CHECKed. Do this to help debug
a printing crash that happens to users but not with any printing tests.

Bug: 1121077
Change-Id: Ieac894c4efdb67f028de13fc2a4bf5ed3a84c258
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2373217Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801268}

third_party/blink/renderer/core/frame/web_local_frame_impl.cc

@@ -676,9 +676,7 @@ void WebLocalFrameImpl::Close() {
   if (print_context_)
     PrintEnd();
   print_client_.reset();
-#if DCHECK_IS_ON()
   is_in_printing_ = false;
-#endif
 }
 
 WebString WebLocalFrameImpl::AssignedName() const {
@@ -1539,12 +1537,10 @@ WebPlugin* WebLocalFrameImpl::FocusedPluginIfInputMethodSupported() {
 
 void WebLocalFrameImpl::DispatchBeforePrintEvent(
     base::WeakPtr<WebPrintClient> print_client) {
-#if DCHECK_IS_ON()
-  DCHECK(!is_in_printing_) << "DispatchAfterPrintEvent() should have been "
-                              "called after the previous "
-                              "DispatchBeforePrintEvent() call.";
+  CHECK(!is_in_printing_) << "DispatchAfterPrintEvent() should have been "
+                             "called after the previous "
+                             "DispatchBeforePrintEvent() call.";
   is_in_printing_ = true;
-#endif
 
   print_client_ = print_client;
 
@@ -1560,11 +1556,9 @@ void WebLocalFrameImpl::DispatchBeforePrintEvent(
 }
 
 void WebLocalFrameImpl::DispatchAfterPrintEvent() {
-#if DCHECK_IS_ON()
-  DCHECK(is_in_printing_) << "DispatchBeforePrintEvent() should be called "
-                             "before DispatchAfterPrintEvent().";
+  CHECK(is_in_printing_) << "DispatchBeforePrintEvent() should be called "
+                            "before DispatchAfterPrintEvent().";
   is_in_printing_ = false;
-#endif
 
   print_client_.reset();
 

third_party/blink/renderer/core/frame/web_local_frame_impl.h

@@ -541,11 +541,11 @@ class CORE_EXPORT WebLocalFrameImpl final
   // cleared upon close().
   SelfKeepAlive<WebLocalFrameImpl> self_keep_alive_;
 
-#if DCHECK_IS_ON()
   // True if DispatchBeforePrintEvent() was called, and
   // DispatchAfterPrintEvent() is not called yet.
+  // TODO(crbug.com/1121077) After fixing the bug, make this member variable
+  // only available when DCHECK_IS_ON().
   bool is_in_printing_ = false;
-#endif
 };
 
 template <>