DevTools: Make WebDevToolsAgent load processId from its client.

Review URL: https://codereview.chromium.org/381403002

git-svn-id: svn://svn.chromium.org/blink/trunk@178030 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Search across files should work for file:folderName queries.

BUG=368216

Review URL: https://codereview.chromium.org/376163002

git-svn-id: svn://svn.chromium.org/blink/trunk@178031 bbb929c8-8fbe-4397-9dbb-9b2b20218538