base: Change DCHECK_IS_ON to a macro DCHECK_IS_ON().

android_webview/browser/hardware_renderer.cc

Index: android_webview/browser/hardware_renderer.cc
diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index 1449541c51fb2614c7e9eba60cd124bbcf25a53d..bded8b91fb3ad156bad0ad2df67f9e9476785956 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -117,13 +117,13 @@ HardwareRenderer::~HardwareRenderer() {
   root_layer_ = NULL;
   delegated_layer_ = NULL;
   frame_provider_ = NULL;
-#if DCHECK_IS_ON

[Nico, 2015/01/06 23:46:15]

Can we make DCHECK_IS_ON a function-style macro? `#if DCHECK_IS_ON()` will fail
instead of silently be 0, and we don't need double negation that way.

[danakj, 2015/01/06 23:55:10]

Oh that's a good point. I thought no, because we used to have that and it was a
problem. But that's because it resolved to code that had to execute at runtime,
not just to a constant that the preprocessor can use.

+#if !DCHECK_IS_OFF
   // Check collection is empty.
   cc::ReturnedResourceArray returned_resources;
   resource_collection_->TakeUnusedResourcesForChildCompositor(
       &returned_resources);
   DCHECK_EQ(0u, returned_resources.size());
-#endif  // DCHECK_IS_ON
+#endif  // !DCHECK_IS_OFF
 
   resource_collection_->SetClient(NULL);