ObserverList::HasObserver now takes a const pointer.

Updated all clients that wrap HasObserver and expose it to also take a
const pointer. This change avoids further propagation of non-constness
(which was previously required when using HasObserver methods).

BUG=429588
TBR=michaeln@chromium.org,nyquist@chromium.org,pkotwicz@chromium.org,satorux@chromium.org,sky@chromium.org,zea@chromium.org

Review URL: https://codereview.chromium.org/697953002

Cr-Commit-Position: refs/heads/master@{#303428}

2 files changed, 5 insertions, 4 deletions

diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index cc44cec..35443f4 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -312,7 +312,7 @@ void Compositor::RemoveObserver(CompositorObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
-bool Compositor::HasObserver(CompositorObserver* observer) {
+bool Compositor::HasObserver(const CompositorObserver* observer) const {
   return observer_list_.HasObserver(observer);
 }
 
@@ -326,7 +326,8 @@ void Compositor::RemoveAnimationObserver(
   animation_observer_list_.RemoveObserver(observer);
 }
 
-bool Compositor::HasAnimationObserver(CompositorAnimationObserver* observer) {
+bool Compositor::HasAnimationObserver(
+    const CompositorAnimationObserver* observer) const {
   return animation_observer_list_.HasObserver(observer);
 }
 
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index a6520a2..a5dc5d0 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -216,11 +216,11 @@ class COMPOSITOR_EXPORT Compositor
   // observer to remove itself when it is done observing.
   void AddObserver(CompositorObserver* observer);
   void RemoveObserver(CompositorObserver* observer);
-  bool HasObserver(CompositorObserver* observer);
+  bool HasObserver(const CompositorObserver* observer) const;
 
   void AddAnimationObserver(CompositorAnimationObserver* observer);
   void RemoveAnimationObserver(CompositorAnimationObserver* observer);
-  bool HasAnimationObserver(CompositorAnimationObserver* observer);
+  bool HasAnimationObserver(const CompositorAnimationObserver* observer) const;
 
   // Creates a compositor lock. Returns NULL if it is not possible to lock at
   // this time (i.e. we're waiting to complete a previous unlock).