Add a command-line switch --enable-per-tile-painting.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index b4e9a27314750cfb6cd9bf698066fbbc443c7db4..1f3d5b1057ca90f6c1019fbb60b259c58763e42e 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -4730,11 +4730,11 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_COMPOSITED_LAYER_BORDERS_DESCRIPTION" desc="Description of the 'Composited layer borders' lab.">
         Renders a border around composited Render Layers to help debug and study layer compositing.
       </message>
-      <message name="IDS_FLAGS_ACCELERATED_DRAWING_NAME" desc="Title for the flag to enable accelerated drawing">
-        GPU Accelerated Drawing
+      <message name="IDS_FLAGS_ACCELERATED_PAINTING_NAME" desc="Title for the flag to enable accelerated painting">
+        GPU Accelerated Painting
       </message>
-      <message name="IDS_FLAGS_ACCELERATED_DRAWING_DESCRIPTION" desc="Description for the flag to enable accelerated drawing">
-        Enable GPU accelerated drawing of page contents when compositing is enabled.
+      <message name="IDS_FLAGS_ACCELERATED_PAINTING_DESCRIPTION" desc="Description for the flag to enable accelerated painting">
+        Enable GPU accelerated painting of page contents when compositing is enabled.
       </message>
       <message name="IDS_FLAGS_SHOW_FPS_COUNTER" desc="Name of the 'Show FPS counter' lab.">
         FPS counter
@@ -5004,6 +5004,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_ENABLE_GAMEPAD_DESCRIPTION" desc="Description for the flag to enable gamepad support.">
         This API allows web applications to access data from gamepad devices connected to the system.
       </message>
+      <message name="IDS_FLAGS_PER_TILE_PAINTING_NAME" desc="Title for the flag to enable per-tile painting">
+        Per-tile Painting
+      </message>
+      <message name="IDS_FLAGS_PER_TILE_PAINTING_DESCRIPTION" desc="Description for the flag to enable per-tile painting">
+        Enable per-tile painting of page contents when compositing is enabled.
+      </message>
 
       <!-- Crashes -->
       <message name="IDS_CRASHES_TITLE" desc="Title for the chrome://crashes page.">