Revert of PlzNavigate: Fix for the PhishingDOMFeatureExtractorTest.SubFrames and SubframeRemoval tes

Revert of PlzNavigate: Fix for the PhishingDOMFeatureExtractorTest.SubFrames  and SubframeRemoval tests (patchset #6 id:100001 of https://codereview.chromium.org/2470413004/ )

Reason for revert:
This isn't needed anymore after r437654

Original issue's description:
> PlzNavigate: Fix for the PhishingDOMFeatureExtractorTest.SubFrames  and SubframeRemoval tests
> 
> The PhishingDOMFeatureExtractorTest tests instantiate the renderer side of the navigation
> code namely RenderFrameImpl, RenderView, etc. However the browser side of the navigation
> is not instantiated. The navigation code in RenderFrame checks for whether browser side
> navigation is enabled and sends IPCs etc which don't work for the tests as written.
> 
> Proposed fix is to provide a way to mock the IPCs being sent in the codepaths being
> exercised in these tests. Specifically the FrameHostMsg_BeginNavigation and FrameMsg_CommitNavigation
> IPCs. To achieve this we provide a way to subclass the ChromeMockRenderThread class which
> is instantiated by the ChromeRenderViewTest class. This is achieved via a virtual function
> CreateMockRenderThread(). This function is overridden by a new class PhishingMockRenderThread
> which is instantiated for the duration of the PhishingDOMFeatureExtractorTest.* tests.
> 
> The other alternative was to make these tests full fledged browser tests which would be a touch
> difficult given the way these tests have been written.
> 
> BUG=662268
> TBR=jam
> 
> Committed: https://crrev.com/5fc8d8d462127a0f20651df4c8a8971926f21f50
> Cr-Commit-Position: refs/heads/master@{#430811}

TBR=nparker@chromium.org,ananta@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=662268

[jam, 2016-12-09 23:14:50]

The CQ bit was checked by jam@chromium.org

[jam, 2016-12-09 23:14:51]

Created Revert of PlzNavigate: Fix for the
PhishingDOMFeatureExtractorTest.SubFrames  and SubframeRemoval tests

[jam, 2016-12-09 23:17:08]

The CQ bit was unchecked by jam@chromium.org

[Nathan Parker, 2016-12-10 00:59:14]

nparker@chromium.org changed reviewers:
+ jialiul@chromium.org