Change trace category for image data judgement in GpuImageDecodeCache

This modification changes two trace operations for
"GetDecodedImageForDraw()" and "DrawWithImageFinished()"
from "cc"to "cc.debug" category. While running Canvas 2D
workloads with quite a lot canvas elements to be drawn,
excessive trace operations introduce expensive performance
overheads, especially for those hardware platforms with
integrated graphics cards or old graphics drivers.

Bug: 1051385

Change-Id: I7cb1b7a3afcb207ac6b7791f21dc621a20e42864
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2059771Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745468}

cc/tiles/gpu_image_decode_cache.cc

@@ -1186,7 +1186,8 @@ bool GpuImageDecodeCache::UseCacheForDrawImage(
 
 DecodedDrawImage GpuImageDecodeCache::GetDecodedImageForDraw(
     const DrawImage& draw_image) {
-  TRACE_EVENT0("cc", "GpuImageDecodeCache::GetDecodedImageForDraw");
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
+               "GpuImageDecodeCache::GetDecodedImageForDraw");
 
   // We are being called during raster. The context lock must already be
   // acquired by the caller.
@@ -1253,7 +1254,8 @@ DecodedDrawImage GpuImageDecodeCache::GetDecodedImageForDraw(
 void GpuImageDecodeCache::DrawWithImageFinished(
     const DrawImage& draw_image,
     const DecodedDrawImage& decoded_draw_image) {
-  TRACE_EVENT0("cc", "GpuImageDecodeCache::DrawWithImageFinished");
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
+               "GpuImageDecodeCache::DrawWithImageFinished");
 
   // Release decoded_draw_image to ensure the referenced SkImage can be
   // cleaned up below.