Remove duplicated WebGL layout tests.

third_party/WebKit/LayoutTests/fast/canvas/webgl/get-active-test-expected.txt

-CONSOLE WARNING: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
-Test of getActiveAttrib and getActiveUniform
-
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
-
-PASS getError was expected value: NO_ERROR : 
-PASS context.getActiveUniform(program, 0).name is 'u_modelViewProjMatrix'
-PASS context.getActiveUniform(program, 0).type is context.FLOAT_MAT4
-PASS context.getActiveUniform(program, 0).size is 1
-PASS context.getActiveUniform(program, 1) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS context.getActiveUniform(program, -1) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS context.getActiveUniform(null, 0) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS info[ii] is non-null.
-PASS info[ii] is non-null.
-PASS info[ii].name is expected[ii].name
-PASS info[ii].type is expected[ii].type
-PASS info[ii].size is expected[ii].size
-PASS info[ii].name is expected[ii].name
-PASS info[ii].type is expected[ii].type
-PASS info[ii].size is expected[ii].size
-PASS info2[ii] is non-null.
-PASS info2[ii] is non-null.
-PASS info2[ii].name is expected2[ii].name
-PASS info2[ii].type is expected2[ii].type
-PASS info2[ii].size is expected2[ii].size
-PASS info2[ii].name is expected2[ii].name
-PASS info2[ii].type is expected2[ii].type
-PASS info2[ii].size is expected2[ii].size
-PASS context.getActiveAttrib(program, 2) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS context.getActiveAttrib(program, -1) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS context.getActiveAttrib(null, 0) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS getError was expected value: NO_ERROR : 
-Check trying to get attribs from different context
-PASS context2.getActiveAttrib(program, 0) is null
-PASS getError was expected value: INVALID_OPERATION : 
-PASS context2.getActiveUniform(program, 0) is null
-PASS getError was expected value: INVALID_OPERATION : 
-Check trying to get attribs from deleted program
-PASS context.getActiveUniform(program, 0) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS context.getActiveAttrib(program, 0) is null
-PASS getError was expected value: INVALID_VALUE : 
-PASS successfullyParsed is true
-
-TEST COMPLETE
-