Implement Sec-CH-UA-Arch for the Mac

Bug: 1110914
Change-Id: I5d6375da9a9e9855e5a8b568fcd9914e39fa94f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2382228Reviewed-by: Aaron Tagliaboschi <aarontag@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803261}

chrome/browser/chrome_content_browser_client_unittest.cc

@@ -753,11 +753,11 @@ TEST(ChromeContentBrowserClientTest, GenerateBrandVersionList) {
 TEST(ChromeContentBrowserClientTest, LowEntropyCpuArchitecture) {
   std::string arch = content::GetLowEntropyCpuArchitecture();
 
-#if (!defined(OS_POSIX) && !defined(OS_WIN)) || defined(OS_MAC) || \
-    defined(OS_ANDROID)
-  EXPECT_EQ("", arch);
-#elif (defined(OS_POSIX) && !defined(OS_MAC)) || defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_MAC) || \
+    (defined(OS_POSIX) && !defined(OS_ANDROID))
   EXPECT_TRUE("arm" == arch || "x86" == arch);
+#else
+  EXPECT_EQ("", arch);
 #endif
 }
 

content/common/user_agent.cc

@@ -15,6 +15,10 @@
 #include "build/lacros_buildflags.h"
 #include "build/util/webkit_version.h"
 
+#if defined(OS_MAC)
+#include "base/mac/mac_util.h"
+#endif
+
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #elif defined(OS_POSIX) && !defined(OS_MAC)
@@ -90,10 +94,27 @@ std::string BuildCpuInfo() {
   return cpuinfo;
 }
 
-// Return the CPU architecture in Linux or Windows and the empty string
+// Return the CPU architecture in Windows/Mac/POSIX and the empty string
 // elsewhere.
 std::string GetLowEntropyCpuArchitecture() {
-#if !defined(OS_MAC) && !defined(OS_ANDROID) && defined(OS_POSIX)
+#if defined(OS_WIN)
+  base::win::OSInfo::WindowsArchitecture windows_architecture =
+      base::win::OSInfo::GetInstance()->GetArchitecture();
+  if (windows_architecture == base::win::OSInfo::ARM64_ARCHITECTURE) {
+    return "arm";
+  } else if ((windows_architecture == base::win::OSInfo::X86_ARCHITECTURE) ||
+             (windows_architecture == base::win::OSInfo::X64_ARCHITECTURE)) {
+    return "x86";
+  }
+#elif defined(OS_MAC)
+  base::mac::CPUType cpu_type = base::mac::GetCPUType();
+  if (cpu_type == base::mac::CPUType::kIntel) {
+    return "x86";
+  } else if (cpu_type == base::mac::CPUType::kArm ||
+             cpu_type == base::mac::CPUType::kTranslatedIntel) {
+    return "arm";
+  }
+#elif defined(OS_POSIX) && !defined(OS_ANDROID)
   // This extra cpu_info_str variable is required to make sure the compiler
   // doesn't optimize the copy away and have the StringPiece point at the
   // internal std::string, resulting in a memory violation.
@@ -107,15 +128,6 @@ std::string GetLowEntropyCpuArchitecture() {
              base::StartsWith(cpu_info, "x86")) {
     return "x86";
   }
-#elif defined(OS_WIN)
-  base::win::OSInfo::WindowsArchitecture windows_architecture =
-      base::win::OSInfo::GetInstance()->GetArchitecture();
-  if (windows_architecture == base::win::OSInfo::ARM64_ARCHITECTURE) {
-    return "arm";
-  } else if ((windows_architecture == base::win::OSInfo::X86_ARCHITECTURE) ||
-             (windows_architecture == base::win::OSInfo::X64_ARCHITECTURE)) {
-    return "x86";
-  }
 #endif
   return std::string();
 }