Change "FPS meter" to "Frame Rendering Stats"

With this CL landed:
https://chromium-review.googlesource.com/c/chromium/src/+/2244002

The fps meter now have a completely new look, and it is actually
showing the throughput of the page. This CL changes the name of
"FPS meter" to "Frame Rendering Stats". Its description is also
updated.

The corresponding devtool front end changes is here
https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2269939

Bug: None
Change-Id: I22cc52abd37e12bb80db99daec339d467d4595f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2268398
Commit-Queue: Xida Chen <xidachen@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#783896}

cc/layers/heads_up_display_layer.cc

@@ -41,7 +41,7 @@ void HeadsUpDisplayLayer::UpdateLocationAndSize(
     bounds = device_viewport_in_layout_pixels;
   } else {
     // If the HUD is not displaying full-viewport rects (e.g., it is showing the
-    // FPS meter), use a fixed size.
+    // Frame Rendering Stats), use a fixed size.
     constexpr int kDefaultHUDSize = 256;
     bounds.SetSize(kDefaultHUDSize, kDefaultHUDSize);
   }

cc/layers/heads_up_display_layer_impl.cc

@@ -664,7 +664,7 @@ SkRect HeadsUpDisplayLayerImpl::DrawFrameThroughputDisplay(
       SkRect::MakeXYWH(left + kPadding, text_bounds.bottom() + 2 * kPadding,
                        kGraphWidth, kGraphHeight);
 
-  // Draw the fps meter.
+  // Draw the frame rendering stats.
   const std::string title("Frames");
   const std::string value_text = base::StringPrintf("%d %%", throughput_value_);
   const std::string dropped_frames_text =

docs/how_cc_works.md

@@ -178,7 +178,7 @@ ChromeOS uses PaintedOverlayScrollbarLayer, which is a nine-patch bitmap version
 ### HeadsUpDisplayLayer
 
 This layer supports [devtools rendering settings](https://developer.chrome.com/devtools/docs/rendering-settings).
-It draws an FPS meter, as well as overlays for paint invalidation or damage.
+It draws an Frame Rendering Stats, as well as overlays for paint invalidation or damage.
 This layer is special because it must be updated last because its inputs depend on all of the other layers’ damage calculations.
 
 ### UIResourceLayer / NinePatchLayer