Update ui::CompositorObserver instrumentation

ui/compositor/compositor_observer.cc

Index: ui/compositor/compositor_observer.cc
diff --git a/ui/compositor/compositor_observer.cc b/ui/compositor/compositor_observer.cc
index 209cd5220b38b46c6c206447e39c75795379554f..5c8cf1a7948def9a5a2732b6b7b10bab25fa421d 100644
--- a/ui/compositor/compositor_observer.cc
+++ b/ui/compositor/compositor_observer.cc
@@ -8,19 +8,17 @@
 
 namespace ui {
 
-#if defined(OS_MACOSX)
-// Debugging instrumentation for crbug.com/401630.
-// TODO(ccameron): remove this.
+#if DCHECK_IS_ON
 CompositorObserver::CompositorObserver() : observing_count_(0) {}
 #else
 CompositorObserver::CompositorObserver() {}
 #endif
 
 CompositorObserver::~CompositorObserver() {
+  // TODO(ccameron): Make this check not fire on non-Mac platforms.
+  // http://crbug.com/403011
 #if defined(OS_MACOSX)

[danakj, 2014/08/12 20:57:54]

Did you wanna remove this?

[ccameron, 2014/08/12 21:04:24]

Nah, I wanted to keep the DCHECK for Mac, and eventually delete the
defined(OS_MACOSX) -- there are a bazillion crashes if it's on for non-Mac ATM
(I filed a bug against that and assigned it to me).

-  // Debugging instrumentation for crbug.com/401630.
-  // TODO(ccameron): remove this.
-  CHECK_EQ(observing_count_, 0);
+  DCHECK_EQ(observing_count_, 0);
 #endif
 }