Originally reported internally in b/65844132.
Question: is this likely the same as  bug 720530 ?  (note we have a couple of additional failures not mentioned there).

First flake noticed was
LayerTreeHostTilesTestPartialInvalidation.PartialRaster_MultiThread_OneCopy

(log fragment pasted below)

We have also seen these tests fail:
LayerTreeHostTilesTestPartialInvalidation.FullRaster_SingleThread_GpuRaster 
LayerTreeHostTilesTestPartialInvalidation.FullRaster_SingleThread_OneCopy
LayerTreeHostTilesTestPartialInvalidation.PartialRaster_SingleThread_GpuRaster 
LayerTreeHostTilesTestPartialInvalidation.PartialRaster_SingleThread_OneCopy


I think it's hard to pinpoint a CL where the failures started because of low flaky rate. If anything it could be that they were failing for a while and we just noticed more recently - we got a bit more rigorous about tracking test results lately.



[3073:3077:0917/184404.933878:2724845298:ERROR:gles2_cmd_decoder.cc(17987)] [GroupMarkerNotSet( crbug.com/242999 )!:5400CAB9]GL ERROR :GL_INVALID_OPERATION : glCreateAndConsumeTextureCHROMIUM: invalid mailbox name
[3073:3077:0917/184405.078412:2724989831:ERROR:gles2_cmd_decoder.cc(9893)] [GroupMarkerNotSet( crbug.com/242999 )!:D40DCAB9]RENDER WARNING: texture bound to texture unit 0 is not renderable. It maybe non-power-of-2 and have incompatible texture filtering.
[3073:3077:0917/184405.144534:2725055954:ERROR:gles2_cmd_decoder.cc(17333)] [GroupMarkerNotSet( crbug.com/242999 )!:5400CAB9]GL ERROR :GL_INVALID_OPERATION : glCopySubTextureCHROMIUM: destination texture is not defined
[3073:3077:0917/184405.241742:2725153195:ERROR:gles2_cmd_decoder.cc(9893)] [GroupMarkerNotSet( crbug.com/242999 )!:D40DCAB9]RENDER WARNING: texture bound to texture unit 0 is not renderable. It maybe non-power-of-2 and have incompatible texture filtering.
[3073:3073:0917/184405.357974:2725269395:ERROR:pixel_comparator.cc(47)] Number of pixel with an error: 40000
[3073:3073:0917/184405.358087:2725269499:ERROR:pixel_comparator.cc(48)] Error Bounding Box : 0,0 200x200
[3073:3073:0917/184405.391565:2725302986:ERROR:pixel_test_utils.cc(79)] Pixels do not match!
[3073:3073:0917/184405.391745:2725303159:ERROR:pixel_test_utils.cc(80)] Actual: data:image/png;base64,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
[3073:3073:0917/184405.391835:2725303247:ERROR:pixel_test_utils.cc(81)] Expected: data:image/png;base64,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
../../cc/test/layer_tree_pixel_test.cc:121: Failure
Value of: MatchesPNGFile(*result_bitmap_, ref_file_path, *pixel_comparator_)
  Actual: false