content: Improve thread priority for raster threads.

content/browser/gpu/compositor_util.cc

Index: content/browser/gpu/compositor_util.cc
diff --git a/content/browser/gpu/compositor_util.cc b/content/browser/gpu/compositor_util.cc
index 64b5e8737af2ac0be70a35b0123bde38a2ceb8a4..b08c59d29996944f688bee96680075b69f0136db 100644
--- a/content/browser/gpu/compositor_util.cc
+++ b/content/browser/gpu/compositor_util.cc
@@ -169,20 +169,10 @@ bool IsPropertyTreeVerificationEnabled() {
 }
 
 int NumberOfRendererRasterThreads() {
-  int num_processors = base::SysInfo::NumberOfProcessors();
+  int num_raster_threads = base::SysInfo::NumberOfProcessors() / 2;
 
 #if defined(OS_ANDROID)
-  // Android may report 6 to 8 CPUs for big.LITTLE configurations.
-  // Limit the number of raster threads based on maximum of 4 big cores.
-  num_processors = std::min(num_processors, 4);
-#endif
-
-  int num_raster_threads = num_processors / 2;
-
-#if defined(OS_ANDROID)
-  // Limit the number of raster threads to 1 on Android.
-  // TODO(reveman): Remove this when we have a better mechanims to prevent
-  // pre-paint raster work from slowing down non-raster work. crbug.com/504515
+  // Use one thread for foreground raster work on Android.
   num_raster_threads = 1;
 #endif