Revert "Bump WebGL stream to high-priority on Adreno 3xx."

This reverts commit 30e36bcc.

Reason for revert: Display compositor doesn't cause mid-frame flushes any more, so workaround isn't needed.

Original change's description:
> Bump WebGL stream to high-priority on Adreno 3xx.
> 
> WebGL has performance issues on Adreno 3xx when we switch contexts
> from/to the WebGL context mid-frame.
> 
> To avoid this issue, we can bump scheduler priority for the WebGL stream
> to high, avoiding most mid-frame interruptions. In local testing this
> (in combination with a backpressure fix) addresses known issues.
> 
> Bug: 879649, 835353
> Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
> Change-Id: I896456b29f3b80e3e443720b9ce444e6825c1c03
> Reviewed-on: https://chromium-review.googlesource.com/1200242
> Reviewed-by: Nasko Oskov <nasko@chromium.org>
> Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
> Commit-Queue: Eric Karl <ericrk@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#588287}

TBR=nasko@chromium.org,sunnyps@chromium.org,ericrk@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 879649, 835353
Change-Id: I0e0c75f5162789b457c2a4cdfa29dc8557972208
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Reviewed-on: https://chromium-review.googlesource.com/c/1311658
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604505}

content/public/common/gpu_stream_constants.h

@@ -13,7 +13,6 @@ enum {
   kGpuStreamIdDefault,
   kGpuStreamIdWorker,
   kGpuStreamIdMedia,
-  kGpuStreamIdHighPriorityWebGL,
 };
 
 // Used for renderer compositor thread context, WebGL (when high priority is
@@ -33,11 +32,6 @@ const gpu::SchedulingPriority kGpuStreamPriorityMedia =
 const gpu::SchedulingPriority kGpuStreamPriorityWorker =
     gpu::SchedulingPriority::kLow;
 
-// Used for WebGL on devices where a hgih priority context is requested by the
-// |use_high_priority_for_webgl| workaround.
-const gpu::SchedulingPriority kGpuStreamPriorityHighPriorityWebGL =
-    gpu::SchedulingPriority::kHigh;
-
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_GPU_STREAM_CONSTANTS_H_

content/renderer/renderer_blink_platform_impl.cc

@@ -70,7 +70,6 @@
 #include "content/renderer/worker_thread_registry.h"
 #include "device/gamepad/public/cpp/gamepads.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
-#include "gpu/config/gpu_driver_bug_workaround_type.h"
 #include "gpu/config/gpu_info.h"
 #include "gpu/ipc/client/gpu_channel_host.h"
 #include "media/audio/audio_output_device.h"
@@ -1040,19 +1039,12 @@ RendererBlinkPlatformImpl::CreateOffscreenGraphicsContext3DProvider(
   constexpr bool automatic_flushes = true;
   constexpr bool support_locking = false;
 
-  uint32_t stream_id = kGpuStreamIdDefault;
-  gpu::SchedulingPriority priority = kGpuStreamPriorityDefault;
-  if (gpu_channel_host->gpu_feature_info().IsWorkaroundEnabled(
-          gpu::USE_HIGH_PRIORITY_FOR_WEBGL)) {
-    stream_id = kGpuStreamIdHighPriorityWebGL;
-    priority = kGpuStreamPriorityHighPriorityWebGL;
-  }
-
   scoped_refptr<ws::ContextProviderCommandBuffer> provider(
       new ws::ContextProviderCommandBuffer(
           std::move(gpu_channel_host),
-          RenderThreadImpl::current()->GetGpuMemoryBufferManager(), stream_id,
-          priority, gpu::kNullSurfaceHandle, GURL(top_document_web_url),
+          RenderThreadImpl::current()->GetGpuMemoryBufferManager(),
+          kGpuStreamIdDefault, kGpuStreamPriorityDefault,
+          gpu::kNullSurfaceHandle, GURL(top_document_web_url),
           automatic_flushes, support_locking, web_attributes.support_grcontext,
           gpu::SharedMemoryLimits(), attributes,
           ws::command_buffer_metrics::ContextType::WEBGL));

gpu/config/gpu_driver_bug_list.json

@@ -2907,18 +2907,6 @@
         "disable_aimagereader"
       ]
     },
-    {
-      "id":276,
-      "cr_bugs": [835353],
-      "description": "Adreno 3xx requires a high-priority WebGL context to avoid MSAA and performance issues",
-      "os": {
-        "type": "android"
-      },
-      "gl_renderer": "Adreno \\(TM\\) 3.*",
-      "features": [
-        "use_high_priority_for_webgl"
-      ]
-    },
     {
       "id": 279,
       "description": "WindowServer crashes on VMWare bots using CA renderer",

gpu/config/gpu_workaround_list.txt

@@ -98,7 +98,6 @@ unpack_overlapping_rows_separately_unpack_buffer
 use_client_side_arrays_for_stream_buffers
 use_es2_for_oopr
 use_gpu_driver_workaround_for_testing
-use_high_priority_for_webgl
 use_intermediary_for_copy_texture_image
 use_non_zero_size_for_client_side_stream_buffers
 use_unused_standard_shared_blocks