Add new extension APIs related to animation policy.

content/browser/accessibility/browser_accessibility_state_impl.h

Index: content/browser/accessibility/browser_accessibility_state_impl.h
diff --git a/content/browser/accessibility/browser_accessibility_state_impl.h b/content/browser/accessibility/browser_accessibility_state_impl.h
index 4c8884373d6c1ef25ed04c62d47369d1ccb310da..781cf2880f4001213cd41137272937e977b5818d 100644
--- a/content/browser/accessibility/browser_accessibility_state_impl.h
+++ b/content/browser/accessibility/browser_accessibility_state_impl.h
@@ -50,6 +50,8 @@ class CONTENT_EXPORT BrowserAccessibilityStateImpl
   void UpdateHistogramsForTesting() override;
 
   AccessibilityMode accessibility_mode() const { return accessibility_mode_; };
+  const std::string& GetImageAnimationPolicy() const override;
+  void SetImageAnimationPolicy(const std::string& policy) override;
 
   // Adds the given accessibility mode to the current accessibility mode bitmap.
   void AddAccessibilityMode(AccessibilityMode mode);
@@ -81,6 +83,7 @@ class CONTENT_EXPORT BrowserAccessibilityStateImpl
   void AddOrRemoveFromAllWebContents(AccessibilityMode mode, bool add);
 
   AccessibilityMode accessibility_mode_;
+  std::string animation_policy_;
 
   std::vector<base::Closure> histogram_callbacks_;