19. A non-transitory computer-readable storage medium having instructions stored thereon, which instructions when executed by one or more microprocessors cause a user's computing device to: register a capability of a first application installed on the user's computing device to process document URLs of a specific type, the first application configured for native operation outside of a web browser on the user's computing device, wherein the web browser on a user's computing device tracks a declaration of a document URL type in a manifest of the first application of the capability of the first application to open a document corresponding to a document URL which conforms to the declared document URL type, and wherein the web browser maintains a registry of document URL types associated with applications including the first application installed on the user's computing device, the document URL types representing types of document URLs that the applications are coded to open or process, the registry of document URLs types being maintained as a table of the declared document URL types registered by the applications; when a navigation event on the user's computing device leads to a navigated-to-document URL that is of the specific type of document URLs registered to the first application on the user's computing device, present a selection dialog permitting the user to select whether the first application should be launched outside the web browser to process the navigated-to-document URL to open the document; and based on the user selection in the selection dialog, redirect the navigated-to-document URL to the first application and launch the application on the user's computing device to open the document corresponding to the navigated-to-document URL by one of using the navigated-to-document URL redirected to the first application to extract the document from the navigated-to-document URL and using the redirected URL as a unique ID to extract the document from a local cache.
19. A non-transitory computer-readable storage medium having instructions stored thereon, which instructions when executed by one or more microprocessors cause a user's computing device to: register a capability of a first application installed on the user's computing device to process document URLs of a specific type, the first application configured for native operation outside of a web browser on the user's computing device, wherein the web browser on a user's computing device tracks a declaration of a document URL type in a manifest of the first application of the capability of the first application to open a document corresponding to a document URL which conforms to the declared document URL type, and wherein the web browser maintains a registry of document URL types associated with applications including the first application installed on the user's computing device, the document URL types representing types of document URLs that the applications are coded to open or process, the registry of document URLs types being maintained as a table of the declared document URL types registered by the applications; when a navigation event on the user's computing device leads to a navigated-to-document URL that is of the specific type of document URLs registered to the first application on the user's computing device, present a selection dialog permitting the user to select whether the first application should be launched outside the web browser to process the navigated-to-document URL to open the document; and based on the user selection in the selection dialog, redirect the navigated-to-document URL to the first application and launch the application on the user's computing device to open the document corresponding to the navigated-to-document URL by one of using the navigated-to-document URL redirected to the first application to extract the document from the navigated-to-document URL and using the redirected URL as a unique ID to extract the document from a local cache. 24. The non-transitory computer-readable storage medium of claim 19 , wherein the instructions when executed by one or more microprocessors cause a web browser to keep track of the specific URL pattern types registered by all applications installed on the user's computing device.