Indexing native application data

1. A computer-implemented method comprising:

receiving, by a search engine and from a mobile device associated with a particular user and a particular native application, a set of data that is generated by the particular native application on the mobile device, the set of data including (i) data that identifies the particular native application, and (ii) a representation of viewed content, the viewed content being content that was displayed by the particular native application on the user device and determined to be viewed by the particular user;

storing, by the search engine, (i) the data that identifies the particular native application, and (ii) information identifying the particular user of the mobile device; and

using the stored set of data in generating a search result that references the viewed content, the search result being generated in response to a query by the particular user.

2. The method of claim 1 , wherein the representation of viewed content includes keywords from the viewed content, or an identifier associated with the viewed content.

3. The method of claim 1 , wherein the set of data further includes an access control list that specifies whether the viewed content is classified as private content or public content.

4. The method of claim 1 , wherein using the stored set of data in generating the search result comprises:

receiving, from a mobile device, a search query from the mobile device of the particular user;

identifying the viewed content as responsive to the search query;

determining that the particular native application is installed on the mobile device; and

in response to determining that the particular native application is installed on the mobile device, generating a search result that (i) references the viewed content, and (ii) includes a link to the viewed content that, when selected, launches the viewed content in the particular native application.

5. A system comprising:

one or more computers; and

a non-transitory computer-readable medium coupled to the one or more computers having instructions stored thereon, which, when executed by the one or more computers, cause the one or more computers to perform operations comprising:

receiving, by a search engine and from a mobile device associated with a particular user and a particular native application, a set of data that is generated by the particular native application on the mobile device, the set of data including (i) data that identifies the particular native application, and (ii) a representation of viewed content, the viewed content being content that was displayed by the particular native application on the user device and determined to be viewed by the particular user;

storing, by the search engine, (i) the data that identifies the particular native application, and (ii) information identifying the particular user of the mobile device; and

using the stored set of data in generating a search result that references the viewed content, the search result being generated in response to a query by the particular user.

6. The system of claim 5 , wherein the representation of viewed content includes keywords from the viewed content, or an identifier associated with the viewed content.

7. The system of claim 5 , wherein the set of data further includes an access control list that specifies whether the viewed content is classified as private content or public content.

8. The system of claim 5 , wherein using the stored set of data in generating the search result comprises:

receiving, from a mobile device, a search query;

identifying the viewed content as responsive to the search query;

determining that the native application is installed on the mobile device; and

in response to determining that the native application is installed on the mobile device, generating a search result that (i) references the viewed content, and (ii) includes a link to the viewed content that, when selected, launches the viewed content in the native application.