Merge 139416

Merge 139416
> Web Inspector [chromium]: Debugger.globalObjectCleared is not dispatched on reload after renderer swap
> https://bugs.webkit.org/show_bug.cgi?id=106555
> 
> Reviewed by Vsevolod Vlasov.
> 
> Source/WebCore:
> 
> Wrong ::enable was made virtual in the InspectorDebuggerAgent.
> 
> Test: inspector/debugger/debugger-scripts-reload.html
> 
> * inspector/InspectorDebuggerAgent.h:
> (InspectorDebuggerAgent):
> * inspector/PageDebuggerAgent.cpp:
> (WebCore::PageDebuggerAgent::enable):
> (WebCore::PageDebuggerAgent::disable):
> * inspector/PageDebuggerAgent.h:
> (PageDebuggerAgent):
> 
> LayoutTests:
> 
> * http/tests/inspector/debugger-test.js:
> (initialize_DebuggerTest):
> * inspector/debugger/debugger-scripts-reload-expected.txt: Added.
> * inspector/debugger/debugger-scripts-reload.html: Added.

TBR=pfeldman@chromium.org
BUG=169437
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=139602