Index: src/wp-admin/custom-background.php
===================================================================
--- src/wp-admin/custom-background.php	(revision 38295)
+++ src/wp-admin/custom-background.php	(working copy)
@@ -467,7 +467,12 @@
 		if ( ! current_user_can('edit_theme_options') || ! isset( $_POST['attachment_id'] ) ) exit;
 		$attachment_id = absint($_POST['attachment_id']);
 		/** This filter is documented in wp-admin/includes/media.php */
-		$sizes = array_keys(apply_filters( 'image_size_names_choose', array('thumbnail' => __('Thumbnail'), 'medium' => __('Medium'), 'large' => __('Large'), 'full' => __('Full Size')) ));
+		$sizes = array_keys( apply_filters( 'image_size_names_choose', array(
+			'thumbnail' => __( 'Thumbnail' ),
+			'medium' => __( 'Medium' ),
+			'large' => __( 'Large' ),
+			'full' => __( 'Full Size' )
+		), __METHOD__ ) );
 		$size = 'thumbnail';
 		if ( in_array( $_POST['size'], $sizes ) )
 			$size = esc_attr( $_POST['size'] );
Index: src/wp-admin/includes/media.php
===================================================================
--- src/wp-admin/includes/media.php	(revision 38295)
+++ src/wp-admin/includes/media.php	(working copy)
@@ -983,8 +983,9 @@
 	 *
 	 * @since 3.3.0
 	 *
-	 * @param array $size_names Array of image sizes and their names. Default values
-	 *                          include 'Thumbnail', 'Medium', 'Large', 'Full Size'.
+	 * @param array  $size_names Array of image sizes and their names. Default values
+	 *                           include 'Thumbnail', 'Medium', 'Large', 'Full Size'.
+	 * @param string $context    The current context: function name, method name, or media template ID.
 	 */
 	$size_names = apply_filters( 'image_size_names_choose', array(
 		'thumbnail' => __( 'Thumbnail' ),
@@ -991,7 +992,7 @@
 		'medium'    => __( 'Medium' ),
 		'large'     => __( 'Large' ),
 		'full'      => __( 'Full Size' )
-	) );
+	), __FUNCTION__ );
 
 	if ( empty( $check ) ) {
 		$check = get_user_setting('imgsize', 'medium');
Index: src/wp-includes/media-template.php
===================================================================
--- src/wp-includes/media-template.php	(revision 38295)
+++ src/wp-includes/media-template.php	(working copy)
@@ -688,7 +688,7 @@
 						'medium'    => __('Medium'),
 						'large'     => __('Large'),
 						'full'      => __('Full Size'),
-					) );
+					), 'tmpl-attachment-display-settings' );
 
 					foreach ( $sizes as $value => $name ) : ?>
 						<#
@@ -763,7 +763,7 @@
 					'medium'    => __( 'Medium' ),
 					'large'     => __( 'Large' ),
 					'full'      => __( 'Full Size' ),
-				) );
+				), 'tmpl-gallery-settings' );
 
 				foreach ( $size_names as $size => $label ) : ?>
 					<option value="<?php echo esc_attr( $size ); ?>">
@@ -937,7 +937,7 @@
 										'medium'    => __('Medium'),
 										'large'     => __('Large'),
 										'full'      => __('Full Size'),
-									) );
+									), 'tmpl-image-details' );
 
 									foreach ( $sizes as $value => $name ) : ?>
 										<#
Index: src/wp-includes/media.php
===================================================================
--- src/wp-includes/media.php	(revision 38295)
+++ src/wp-includes/media.php	(working copy)
@@ -3117,7 +3117,7 @@
 			'medium'    => __('Medium'),
 			'large'     => __('Large'),
 			'full'      => __('Full Size'),
-		) );
+		), __FUNCTION__ );
 		unset( $possible_sizes['full'] );
 
 		// Loop through all potential sizes that may be chosen. Try to do this with some efficiency.