This directory contains classes that are responsible for interacting with content::WebContents to retrieve information about a web app. This allows the WebAppProvider system to wrap functionality it uses from a content::WebContents in a fake-able dependency, enabling easy unit testing of the system without having to interact with a real content::WebContents, which isn't well supported in unit tests.
This also means that the WebContentsManager's implementation needs to also be thoroughly tested to make sure it performs as expected with a real content::WebContents.
The WebContentsManager is owned by the WebAppProvider. In production code, it should not be accessed directly. Instead, it is accessed through a lock that is acquired by a WebAppCommand (or via a callback scheduled via the WebAppCommandScheduler). The lock is then used to access the WebContentsManager.
See the locks and commands README.md files for more information.
For testing classes that depend on this system, FakeWebContentsManager can be used to fake out the WebContents dependency.
The WebContentsManager is the main class in this directory. It is a factory that is responsible for creating the following classes:
WebAppDataRetriever: Retrieves the WebAppInstallInfo from a WebContents, checks for installability, and can be used to retrieve all icons.WebAppIconDownloader: Downloads the icons for a web app from a WebContents.WebAppUrlLoader: Loads a URL in a WebContents. This class lives in //components/webapps/browser/web_contents/.The classes in this directory are tested using unit tests that inherit from ChromeRenderViewHostTestHarness. These tests use a WebContentsTester to simulate a WebContents and test the logic of the classes in isolation.
See web_app_data_retriever_unittest.cc and web_app_icon_downloader_unittest.cc for examples.
//chrome/browser/web_applications/web_contents/web_contents_manager.h//chrome/browser/web_applications/web_contents/web_app_data_retriever.h//chrome/browser/web_applications/web_contents/web_app_icon_downloader.h//chrome/browser/web_applications/test/fake_web_contents_manager.h//components/webapps/browser/web_contents/web_app_url_loader.h