Fixed reading uninitialized memory in InspectorDatabaseAgent.

BUG=288801

Review URL: https://chromiumcodereview.appspot.com/24251004

git-svn-id: svn://svn.chromium.org/blink/trunk@158114 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove incorrect comment for createXHRTextDecoder

createXHRTextDecoder never returns null.
Removed the incorrect comment and make the createXHRTextDecoder
implementation clear.

BUG=

Review URL: https://chromiumcodereview.appspot.com/23537047

git-svn-id: svn://svn.chromium.org/blink/trunk@158115 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Speedup sourceURL matching

Do not use RegularExpression for sourceURL matching as creation of
a regular expression takes time.

BUG=289714

Review URL: https://chromiumcodereview.appspot.com/24198005

git-svn-id: svn://svn.chromium.org/blink/trunk@158116 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Provide indication of the target tab inactivity in screencast view (Blink side)

BUG=24242004

Review URL: https://chromiumcodereview.appspot.com/24145005

git-svn-id: svn://svn.chromium.org/blink/trunk@158117 bbb929c8-8fbe-4397-9dbb-9b2b20218538