Large wallpaper decoding in utility process

chrome/utility/chrome_content_utility_client_unittest.cc

+// Copyright 2014 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 "chrome/common/chrome_utility_messages.h"
+#include "chrome/utility/chrome_content_utility_client.h"
+#include "ipc/ipc_channel.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/codec/jpeg_codec.h"
+
+bool CreateJPEGImage(int width,

[bshe, 2014/08/29 19:56:26]

nit: wrap this function in a anonymous namespace.

[Greg Levin, 2014/09/04 16:39:19]

Done.

+                     int height,
+                     SkColor color,
+                     std::vector<unsigned char>* output) {
+  SkBitmap bitmap;
+  bitmap.allocN32Pixels(width, height);
+  bitmap.eraseColor(color);
+
+  const int kQuality = 80;
+  if (!gfx::JPEGCodec::Encode(
+          static_cast<const unsigned char*>(bitmap.getPixels()),
+          gfx::JPEGCodec::FORMAT_SkBitmap,
+          width,
+          height,
+          bitmap.rowBytes(),
+          kQuality,
+          output)) {
+    LOG(ERROR) << "Unable to encode " << width << "x" << height << " bitmap";
+    return false;
+  }
+  return true;
+}
+
+typedef testing::Test ChromeContentUtilityClientTest;
+
+// Test that DecodeImage() doesn't return image message > kMaximumMessageSize
+TEST_F(ChromeContentUtilityClientTest, DecodeImageSizeLimit) {
+  // Approx max height for 3:2 image that will fit in IPC message;
+  // 1.5 for width/height ratio, 4 for bytes/pixel
+  int max_height_for_msg = sqrt(IPC::Channel::kMaximumMessageSize/(1.5*4));
+  int height_large = max_height_for_msg + 20;
+  int width_large = height_large*3/2;
+  int height_small = max_height_for_msg - 20;
+  int width_small = height_small*3/2;
+  int base_msg_size = sizeof(ChromeUtilityHostMsg_DecodeImage_Succeeded);
+
+  // Slightly larger than IPC msg limit, dimensions will be halved
+  std::vector<unsigned char> jpg_large;
+  CreateJPEGImage(width_large, height_large, SK_ColorRED, &jpg_large);
+  SkBitmap bitmap_shrunk =
+      ChromeContentUtilityClient::DecodeImage(jpg_large, true);
+
+  EXPECT_EQ(width_large/2, bitmap_shrunk.width());
+  EXPECT_EQ(height_large/2, bitmap_shrunk.height());
+  EXPECT_LT(bitmap_shrunk.computeSize64() + base_msg_size,
+              static_cast<int64_t>(IPC::Channel::kMaximumMessageSize));

[bshe, 2014/08/29 19:56:26]

nit: indent

[Greg Levin, 2014/09/04 16:39:19]

Done.

+

[Tom Sepez, 2014/08/29 19:51:09]

how about 4x just to run your loop more than once?

[Greg Levin, 2014/09/04 16:39:19]

Done.  Also added check for "shrink_to_fit == false" case.

+  // Slightly smaller than IPC msg limit, dimensions will be unchanged
+  std::vector<unsigned char> jpg_small;
+  CreateJPEGImage(width_small, height_small, SK_ColorRED, &jpg_small);
+  SkBitmap bitmap_unshrunk =
+      ChromeContentUtilityClient::DecodeImage(jpg_small, true);
+
+  EXPECT_EQ(width_small, bitmap_unshrunk.width());
+  EXPECT_EQ(height_small, bitmap_unshrunk.height());
+  EXPECT_LT(bitmap_unshrunk.computeSize64() + base_msg_size,
+              static_cast<int64_t>(IPC::Channel::kMaximumMessageSize));
+}