Note: this list is generated by looking for the string for this theme hook, so it may include some references that are not actually using this theme hook.

hook_block_view in core/modules/layout/layout.api.php
Return a rendered or renderable view of a block.
hook_user_view in core/modules/user/user.api.php
The user's account information is being displayed.
template_preprocess_comment in core/modules/comment/
Preprocesses variables for comment.tpl.php.
template_preprocess_node in core/modules/node/
Processes variables for node.tpl.php.
template_preprocess_user_picture in core/modules/user/
Process variables for user-picture.tpl.php.
TokenUserTestCase::testUserTokens in core/modules/simpletest/tests/token.test
user_account_form in core/modules/user/user.module
Helper function to add default user account fields to user registration and edit form.
user_theme in core/modules/user/user.module
Implements hook_theme().
user_tokens in core/modules/user/
Implements hook_tokens().
user_user_view in core/modules/user/user.module
Implements hook_user_view().
views_handler_field_user_picture::render in core/modules/user/views/
Render the field.