[Extensions Bindings] Remove guards around getInternalApi in //chromecast

Custom bindings in JS files used to require guards around
getInternalApi, since it was only set if native extension bindings were
used. Now that native extension bindings are the only form of bindings,
we can remove the guards and JS versions of the same invocations.

Bug: 938998

Change-Id: I0c79d23f5fe759b86ea5abf7d168df777d844753
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1544090Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#645553}

chromecast/renderer/resources/extensions/automation/automation_node.js

@@ -3,10 +3,7 @@
 // found in the LICENSE file.
 
 var AutomationEvent = require('automationEvent').AutomationEvent;
-var automationInternal =
-    getInternalApi ?
-        getInternalApi('automationInternal') :
-        require('binding').Binding.create('automationInternal').generate();
+var automationInternal = getInternalApi('automationInternal');
 var exceptionHandler = require('uncaught_exception_handler');
 
 var natives = requireNative('automationInternal');

chromecast/renderer/resources/extensions/automation_custom_bindings.js

@@ -5,10 +5,7 @@
 // Custom bindings for the automation API.
 var AutomationNode = require('automationNode').AutomationNode;
 var AutomationRootNode = require('automationNode').AutomationRootNode;
-var automationInternal =
-    getInternalApi ?
-        getInternalApi('automationInternal') :
-        require('binding').Binding.create('automationInternal').generate();
+var automationInternal = getInternalApi('automationInternal');
 var exceptionHandler = require('uncaught_exception_handler');
 var logging = requireNative('logging');
 var nativeAutomationInternal = requireNative('automationInternal');