Notable PDF Viewer is made for the cloud and does a wonderful job integrating with Google Drive. Highlights of the app include,
- Never lose anything
- Powerful PDF Viewer
- Offline Support
- Google Drive, Dropbox & Box.net Integration
The only word of caution with text selection is when pasteing text make sure your choose "paste as plain text". If you just paste it, all mark up will be included and the page gets weird.
In the video below I use the Linux Mint handbook to demonstrate the feature of the Notable PDF Viewer.