Decouple some graphics-related IsLowEndDevice() policies for 1GB devices.

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index b4d13ee0391c6928c3187b376a7f9af74c67bd3e..f572bb644c23f4ebc8b8936dd00c1de9de3a2b6f 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -169,7 +169,7 @@ gpu::gles2::ContextCreationAttribHelper GetCompositorContextAttributes(
 
   if (has_transparent_background) {
     attributes.alpha_size = 8;
-  } else if (base::SysInfo::IsLowEndDevice()) {
+  } else if (base::SysInfo::AmountOfPhysicalMemoryMB() <= 512) {
     // In this case we prefer to use RGB565 format instead of RGBA8888 if
     // possible.
     // TODO(danakj): GpuCommandBufferStub constructor checks for alpha == 0 in