Remove support for old version of Xcode.

As Xcode 9.0+ is required to build Chrome on iOS, remove
supports for older versions.

Bug: none
Change-Id: Idf2e9516cb8f508109e22f3afaef8cd56ad94eb5
Reviewed-on: https://chromium-review.googlesource.com/763409
Reviewed-by: Elodie Banel <lod@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515984}

build/config/compiler/BUILD.gn

@@ -1304,9 +1304,7 @@ config("default_warnings") {
         "-Wno-tautological-constant-compare",
         "-Wtautological-constant-out-of-range-compare",
       ]
-    } else if (use_xcode_clang && xcode_version_int >= 830) {
-      # This is necessary to allow a progressive transition from using xcode 8.0
-      # to 8.3 or more recent. Remove when all bots are migrated to 8.3.
+    } else if (use_xcode_clang) {
       cflags += [
         # TODO(thakis): https://crbug.com/604888
         "-Wno-undefined-var-template",

build/config/ios/ios_sdk.gni

@@ -110,7 +110,6 @@ if (ios_sdk_path == "") {
   ios_sdk_build = _ios_sdk_result.sdk_build
   xcode_version = _ios_sdk_result.xcode_version
   xcode_version_int = _ios_sdk_result.xcode_version_int
-  assert(xcode_version_int >= 900, "Xcode 9 is required.")
   xcode_build = _ios_sdk_result.xcode_build
   machine_os_build = _ios_sdk_result.machine_os_build
   if (use_ios_simulator) {
@@ -169,3 +168,5 @@ if (ios_enable_code_signing && !use_ios_simulator) {
     }
   }
 }
+
+assert(xcode_version_int >= 900, "Xcode 9 is required.")

build/config/ios/rules.gni

@@ -1928,10 +1928,10 @@ template("ios_xcuitest_test_runner_bundle") {
     # Xcode needs the following frameworks installed in the application
     # (and signed) for the XCUITest to run, so install them using
     # extra_system_frameworks.
-    extra_system_frameworks = [ "$ios_sdk_platform_path/Developer/Library/Frameworks/XCTest.framework" ]
-    if (xcode_version_int >= 900) {
-      extra_system_frameworks += [ "$ios_sdk_platform_path/Developer/Library/PrivateFrameworks/XCTAutomationSupport.framework" ]
-    }
+    extra_system_frameworks = [
+      "$ios_sdk_platform_path/Developer/Library/Frameworks/XCTest.framework",
+      "$ios_sdk_platform_path/Developer/Library/PrivateFrameworks/XCTAutomationSupport.framework",
+    ]
 
     bundle_deps = [
       ":$_info_plist_bundle",