Tracing category 'gpu_decoder' does not reflect implementation naming

'gpu.decoder' is used in decoders and mismatches chrome://tracing UI.
Resulting in gpu.decoder always disabled.
Rename CL was:
https://chromium-review.googlesource.com/c/chromium/src/+/1334229

Expected behavior: when recording with gpu.decoder, gpu.device and
gpu.service, there should be slices with category
"disabled-by-default-gpu.decoder".

Change-Id: I074a938ce79e05da2b6f931dca35f8f6864fd0c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2024070Reviewed-by: Eric Seckler <eseckler@chromium.org>
Reviewed-by: kylechar <kylechar@chromium.org>
Commit-Queue: Kramer Ge <fangzhoug@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737350}

base/trace_event/builtin_categories.h

@@ -182,7 +182,7 @@
   X(TRACE_DISABLED_BY_DEFAULT("gpu_cmd_queue"))                          \
   X(TRACE_DISABLED_BY_DEFAULT("gpu.dawn"))                               \
   X(TRACE_DISABLED_BY_DEFAULT("gpu.debug"))                              \
-  X(TRACE_DISABLED_BY_DEFAULT("gpu_decoder"))                            \
+  X(TRACE_DISABLED_BY_DEFAULT("gpu.decoder"))                            \
   X(TRACE_DISABLED_BY_DEFAULT("gpu.device"))                             \
   X(TRACE_DISABLED_BY_DEFAULT("gpu.service"))                            \
   X(TRACE_DISABLED_BY_DEFAULT("histogram_samples"))                      \

components/viz/common/yuv_readback_unittest.cc

@@ -475,7 +475,7 @@ class YUVReadbackTest : public testing::Test {
 
 TEST_F(YUVReadbackTest, YUVReadbackOptTest) {
   for (int use_mrt = 0; use_mrt <= 1; ++use_mrt) {
-    // This test uses the gpu.service/gpu_decoder tracing events to detect how
+    // This test uses the gpu.service/gpu.decoder tracing events to detect how
     // many scaling passes are actually performed by the YUV readback pipeline.
     StartTracing(TRACE_DISABLED_BY_DEFAULT(
         "gpu.service") "," TRACE_DISABLED_BY_DEFAULT("gpu.decoder"));