Add disable_mipmap_generation GPU workaround

This is to provide a workaround for specific low memory devices to
disable mipmap generation which should reduce memory usage.

Bug: 1138979
Change-Id: I214a01fd57be202cc5c21f850f7de3176871110b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485520Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819511}

gpu/command_buffer/service/shared_context_state.cc

@@ -301,6 +301,7 @@ bool SharedContextState::InitializeGrContext(
     // in GetCapabilities and ensuring these are also used by the
     // PaintOpBufferSerializer.
     GrContextOptions options = GetDefaultGrContextOptions(GrContextType::kGL);
+    options.fSuppressMipmapSupport = workarounds.disable_mipmap_generation;
     options.fDriverBugWorkarounds =
         GrDriverBugWorkarounds(workarounds.ToIntSet());
     options.fPersistentCache = cache;

gpu/config/gpu_workaround_list.txt

@@ -39,6 +39,7 @@ disable_half_float_for_gmb
 disable_imagebitmap_from_video_using_gpu
 disable_larger_than_screen_overlays
 disable_mediafoundation_async_h264_encoding
+disable_mipmap_generation
 disable_multisampling_color_mask_usage
 disable_nv12_dxgi_video
 disable_nv12_dynamic_textures