Plugin Power Saver: Update pixel test tolerance and error behavior.

chrome/browser/plugins/plugin_power_saver_browsertest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdint.h>
 #include <string>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/stl_util.h"
@@ skipping 34 matching lines @@
 const int kBrowserHeight = 700;
 
 // Compare only a portion of the snapshots, as different platforms will
 // capture different sized snapshots (due to differences in browser chrome).
 const int kComparisonWidth = 500;
 const int kComparisonHeight = 600;
 
 // Different platforms have slightly different pixel output, due to different
 // graphics implementations. Slightly different pixels (in BGR space) are still
 // counted as a matching pixel by this simple manhattan distance threshold.
-const int kPixelManhattanDistanceTolerance = 20;
+const int kPixelManhattanDistanceTolerance = 25;
 
 std::string RunTestScript(base::StringPiece test_script,
                           content::WebContents* contents,
                           const std::string& element_id) {
   std::string script = base::StringPrintf(
       "var plugin = window.document.getElementById('%s');"
       "if (plugin === undefined ||"
       "    (plugin.nodeName !== 'OBJECT' && plugin.nodeName !== 'EMBED')) {"
       "  window.domAutomationController.send('error');"
       "} else {"
@@ skipping 117 matching lines @@
     return false;
   }
 
   if (w < kComparisonWidth || h < kComparisonHeight)
     return false;
 
   int32_t* ref_pixels = reinterpret_cast<int32_t*>(decoded.data());
   SkAutoLockPixels lock_image(bitmap);
   int32_t* pixels = static_cast<int32_t*>(bitmap.getPixels());
 
-  int stride = bitmap.rowBytes();
+  bool success = true;
   for (int y = 0; y < kComparisonHeight; ++y) {
     for (int x = 0; x < kComparisonWidth; ++x) {
-      int32_t pixel = pixels[y * stride / sizeof(int32_t) + x];
+      int32_t pixel = pixels[y * bitmap.rowBytes() / sizeof(int32_t) + x];
       int pixel_b = pixel & 0xFF;
       int pixel_g = (pixel >> 8) & 0xFF;
       int pixel_r = (pixel >> 16) & 0xFF;
 
       int32_t ref_pixel = ref_pixels[y * w + x];
       int ref_pixel_b = ref_pixel & 0xFF;
       int ref_pixel_g = (ref_pixel >> 8) & 0xFF;
       int ref_pixel_r = (ref_pixel >> 16) & 0xFF;
 
       int manhattan_distance = abs(pixel_b - ref_pixel_b) +
                                abs(pixel_g - ref_pixel_g) +
                                abs(pixel_r - ref_pixel_r);
 
       if (manhattan_distance > kPixelManhattanDistanceTolerance) {
         ADD_FAILURE() << "Pixel test failed on (" << x << ", " << y << "). " <<
             "Pixel manhattan distance: " << manhattan_distance << ".";
-        return false;
+        success = false;
       }
     }
   }
 
-  return true;
+  return success;
 }
 
 // |snapshot_matches| is set to true if the snapshot matches the reference and
 // the test passes. Otherwise, set to false.
 void CompareSnapshotToReference(const base::FilePath& reference,
                                 bool* snapshot_matches,
                                 const base::Closure& done_cb,
                                 const SkBitmap& bitmap,
                                 content::ReadbackResponse response) {
   DCHECK(snapshot_matches);
@@ skipping 404 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, ZoomIndependent) {
   ui_zoom::ZoomController::FromWebContents(GetActiveWebContents())
       ->SetZoomLevel(4.0);
   LoadHTML(
       "<object id='plugin' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='200'>"
       "</object>");
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin");
 }