Remove repeated doRun() calls in video_to_sub_texture perf test

A recent change intentionally stopped caching SkImage readbacks.

This benchmark results in a single video frame being requested multiple
times, forcing multiple readbacks into CPU memory. This is not
representative of a real world regression, as applications are expected
to cache any uploaded WebGL textures themselves.

See discussion on bug for more details.

Bug: 1115128
Change-Id: I4de6fc4bfb82f5c6baf1778342f2c4c9bfc0c3cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437470Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Khushal <khushalsagar@chromium.org>
Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Jonah Chin <jochin@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#815820}

tools/perf/page_sets/rendering/simple_canvas_cases.py

@@ -164,7 +164,26 @@ class VideoToHWAcceleratedCanvas(SimpleCanvasPage):
 
 class VideoToSubTexture(SimpleCanvasPage):
   BASE_NAME = 'video_to_sub_texture'
-  URL = 'file://../simple_canvas/video_to_sub_texture.html'
+  # pylint: disable=line-too-long
+  URL = 'file://../simple_canvas/video_to_sub_texture.html?flip_y=false&premult=false'
+
+
+class VideoToSubTextureFlipY(SimpleCanvasPage):
+  BASE_NAME = 'video_to_sub_texture_flip_y'
+  # pylint: disable=line-too-long
+  URL = 'file://../simple_canvas/video_to_sub_texture.html?flip_y=true&premult=false'
+
+
+class VideoToSubTexturePremultiply(SimpleCanvasPage):
+  BASE_NAME = 'video_to_sub_texture_premultiply'
+  # pylint: disable=line-too-long
+  URL = 'file://../simple_canvas/video_to_sub_texture.html?flip_y=false&premult=true'
+
+
+class VideoToSubTextureFlipAndPremultiply(SimpleCanvasPage):
+  BASE_NAME = 'video_to_sub_texture_flip_and_premultiply'
+  # pylint: disable=line-too-long
+  URL = 'file://../simple_canvas/video_to_sub_texture.html?flip_y=true&premult=true'
 
 
 class VideoToTexture(SimpleCanvasPage):

tools/perf/page_sets/simple_canvas/video_to_sub_texture.html

@@ -19,39 +19,39 @@ function setSize(width, height) {
     canvas3D.height = height;
 }
 
+function getArgValue(argname) {
+    const queryString = window.location.search;
+    const urlParams = new URLSearchParams(queryString);
+    var result = urlParams.get(argname);
+    if (!result) {
+      return false;
+    }
+    return result === "true";
+}
+
 function startPerfTest() {
     preRun();
     perfTest();
 }
 
 function perfTest() {
-    for (i = 0; i < 10; i++) {
-        doRun();
-    }
+    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
+    gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, premultiply);
+    gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, videoElement);
     gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(4));
     requestAnimationFrame(perfTest);
 }
 
-var flipYAndPremultipyAlphas =
-  [[ false, false ],
-   [ false, true  ],
-   [ true,  false ],
-   [ true,  true  ]];
-var optionIndex = 0;
+var flipY = false;
+var premultiply = false;
 var tex = null;
 
 function preRun() {
     tex = gl.createTexture();
     gl.bindTexture(gl.TEXTURE_2D, tex);
     gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, videoElement.videoWidth, videoElement.videoHeight, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
-    optionIndex = 0;
-}
-
-function doRun() {
-    var i = optionIndex++ % flipYAndPremultipyAlphas.length;
-    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipYAndPremultipyAlphas[i][0]);
-    gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, flipYAndPremultipyAlphas[i][1]);
-    gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, videoElement);
+    flipY = getArgValue('flip_y');
+    premultiply = getArgValue('premult');
 }
 
 window.onload = function () {