Enabled SkiaRenderer on low-end devices, except android

crrev.com/808041 disabled SkiaRenderer on all low-end devices. This
broke graphics on Fuchsia (low-end devices with Vulkan is enabled). That
change was Android-specific, so it doesn't make sense on Fuchsia. Moved
corresponding code to #ifdef OS_ANDROID, so it doesn't break other
platforms.

TBR=backer@chromium.org

Bug: 1126490, 1130036
Change-Id: I10842de84e64eca16d8e904b3b1139ca7ad5abdf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2419555Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808629}

components/viz/common/features.cc

@@ -109,16 +109,16 @@ bool IsUsingSkiaRenderer() {
   if (base::android::BuildInfo::GetInstance()->sdk_int() <=
       base::android::SDK_VERSION_KITKAT)
     return false;
+
+  // https://crbug.com/1126490 Mali-400 with <= 512 MB is currently broken.
+  if (base::SysInfo::AmountOfPhysicalMemoryMB() <= 512)
+    return false;
 #endif
 
   // Viz for webview requires SkiaRenderer.
   if (IsUsingVizForWebView())
     return true;
 
-  // https://crbug.com/1126490 Mali-400 with <= 512 MB is currently broken.
-  if (base::SysInfo::AmountOfPhysicalMemoryMB() <= 512)
-    return false;
-
   return base::FeatureList::IsEnabled(kUseSkiaRenderer) ||
          base::FeatureList::IsEnabled(kVulkan);
 }