Move ImageFetcher to its own target.

components/image_fetcher/ios/BUILD.gn

Index: components/image_fetcher/ios/BUILD.gn
diff --git a/ios/chrome/browser/webp_transcode/BUILD.gn b/components/image_fetcher/ios/BUILD.gn
similarity index 50%
rename from ios/chrome/browser/webp_transcode/BUILD.gn
rename to components/image_fetcher/ios/BUILD.gn
index 499ec31ccb2f4cc48494ccfe2055a541b5505f8f..2d52f31c4a1f03a763dc009e10e863b0ec33fb27 100644
--- a/ios/chrome/browser/webp_transcode/BUILD.gn
+++ b/components/image_fetcher/ios/BUILD.gn
@@ -2,42 +2,60 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("webp_transcode") {
+source_set("ios") {
   sources = [
+    "raw_image_fetcher.h",
+    "raw_image_fetcher.mm",
     "webp_decoder.h",
     "webp_decoder.mm",
   ]
   deps = [
     "//base",
+    "//ios/web",
+    "//net",
     "//third_party/libwebp:libwebp_dec",
   ]
 }
 
+source_set("test_support") {
+  testonly = true
+  sources = [
+    "mock_raw_image_fetcher.h",
+    "mock_raw_image_fetcher.mm",
+  ]
+  deps = [
+    ":ios",
+    "//testing/gmock",
+  ]
+}
+
 source_set("unit_tests") {
   testonly = true
   sources = [
+    "raw_image_fetcher_unittest.mm",
     "webp_decoder_unittest.mm",
   ]
   deps = [
-    ":webp_transcode",
+    ":ios",
     ":webp_transcode_unit_tests_bundle_data",
     "//base",
+    "//net",
+    "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
-  libs = [ "CoreGraphics.framework" ]
 }
 
 bundle_data("webp_transcode_unit_tests_bundle_data") {
   visibility = [ ":unit_tests" ]
   testonly = true
   sources = [
-    "//ios/chrome/test/data/webp_transcode/test.jpg",
-    "//ios/chrome/test/data/webp_transcode/test.webp",
-    "//ios/chrome/test/data/webp_transcode/test_alpha.png",
-    "//ios/chrome/test/data/webp_transcode/test_alpha.webp",
-    "//ios/chrome/test/data/webp_transcode/test_small.tiff",
-    "//ios/chrome/test/data/webp_transcode/test_small.webp",
+    "//components/test/data/webp_transcode/test.jpg",
+    "//components/test/data/webp_transcode/test.webp",
+    "//components/test/data/webp_transcode/test_alpha.png",
+    "//components/test/data/webp_transcode/test_alpha.webp",
+    "//components/test/data/webp_transcode/test_small.tiff",
+    "//components/test/data/webp_transcode/test_small.webp",
   ]
   outputs = [
     "{{bundle_resources_dir}}/{{source_root_relative_dir}}/" +