Initialize gl_position for PowerVR* devices

This change applies the existing gpu bug workaround,
init_gl_position_in_vertex_shader, to devices with PowerVR
GPUs. By initializing gl_postion to a known value, a vertex
shader can be created. This allows the following gl_tests
to pass on PowerVR devices:

GLOOBAttribTest.DrawUsingOOBMatrixAttrib

R=piman@chromium.org

TEST=Existing tests pass

Bug: 286468, 416670
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: Iecb91777d093cdd0eb8079dc56aca92f6e4ad93d
Reviewed-on: https://chromium-review.googlesource.com/956531
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543279}

AUTHORS

@@ -455,6 +455,7 @@ Khasim Syed Mohammed <khasim.mohammed@linaro.org>
 Kihong Kwon <kihong.kwon@samsung.com>
 Kihwang Kim <pwangkk@gmail.com>
 Kim Christensen <kimworking@gmail.com>
+Kimberly Hunter <kimberhu@amazon.com>
 Kingshuk Jana <kingshuk.j@samsung.com>
 Kirill Bobyrev <kirillbobyrev@gmail.com>
 Kirill Ovchinnikov <kirill.ovchinn@gmail.com>

gpu/config/gpu_driver_bug_list.json

@@ -2824,6 +2824,45 @@
       "features": [
         "disable_d3d11"
       ]
+    },
+    {
+      "id": 262,
+      "description": "Program fails in PowerVR*GX6250 drivers if gl_Position is not set",
+      "cr_bugs": [286468, 416670],
+      "os": {
+        "type": "android"
+      },
+      "gl_vendor": "Imagination.*",
+      "gl_renderer": "PowerVR.*GX6250",
+      "features": [
+        "init_gl_position_in_vertex_shader"
+      ]
+    },
+    {
+      "id": 263,
+      "description": "Program fails in PowerVR SGX54x drivers if gl_Position is not set",
+      "cr_bugs": [286468, 416670],
+      "os": {
+        "type": "android"
+      },
+      "gl_vendor": "Imagination.*",
+      "gl_renderer": "PowerVR SGX54.",
+      "features": [
+        "init_gl_position_in_vertex_shader"
+      ]
+    },
+    {
+      "id": 264,
+      "description": "Program fails in PowerVR G6200 drivers if gl_Position is not set",
+      "cr_bugs": [286468, 416670],
+      "os": {
+        "type": "android"
+      },
+      "gl_vendor": "Imagination.*",
+      "gl_renderer": "PowerVR G6200",
+      "features": [
+        "init_gl_position_in_vertex_shader"
+      ]
     }
   ]
 }