Chromecast buildfix: satisfy new CreateZoomLevelDelegate API.

R=lcwu@chromium.org,wjmaclean@chromium.org
BUG=None

Review URL: https://codereview.chromium.org/720513003

Cr-Commit-Position: refs/heads/master@{#303862}

chromecast/browser/cast_browser_context.cc

@@ -77,6 +77,12 @@ void CastBrowserContext::InitWhileIOAllowed() {
 #endif  // defined(OS_ANDROID)
 }
 
+scoped_ptr<content::ZoomLevelDelegate>
+CastBrowserContext::CreateZoomLevelDelegate(
+    const base::FilePath& partition_path) {
+  return nullptr;
+}
+
 base::FilePath CastBrowserContext::GetPath() const {
   return path_;
 }

chromecast/browser/cast_browser_context.h

@@ -26,6 +26,8 @@ class CastBrowserContext : public content::BrowserContext {
   virtual ~CastBrowserContext();
 
   // BrowserContext implementation:
+  virtual scoped_ptr<content::ZoomLevelDelegate> CreateZoomLevelDelegate(
+      const base::FilePath& partition_path) override;
   virtual base::FilePath GetPath() const override;
   virtual bool IsOffTheRecord() const override;
   virtual net::URLRequestContextGetter* GetRequestContext() override;