Cache Mac channel information

Soon, with TargetChannel, an instance of Chrome on the disk
might be upgraded to an instance of Chrome of a different
channel. Cache the channel information on startup, so that
even if it's changed, the channel information of the current
running instance is available.

This relands aa20f9b8 with
a fix.

Fixed: 1163159
Change-Id: If1e3da89ff70da765782dd4dbdf0505da67c4e3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2620839Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Auto-Submit: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842079}

chrome/app/chrome_main_delegate.cc

@@ -578,6 +578,10 @@ void ChromeMainDelegate::PostEarlyInitialization(bool is_running_tests) {
 #if defined(OS_ANDROID)
   UmaSessionStats::OnStartup();
 #endif
+
+#if defined(OS_MAC)
+  chrome::CacheChannelInfo();
+#endif
 }
 
 bool ChromeMainDelegate::ShouldCreateFeatureList() {

chrome/common/channel_info.h

@@ -42,6 +42,12 @@ std::string GetChannelName();
 version_info::Channel GetChannel();
 
 #if defined(OS_MAC)
+// Because the channel information on the Mac is baked into the Info.plist file,
+// and that file may change during an update, this function must be called
+// early in startup to cache the channel info so that the correct channel info
+// can be returned later.
+void CacheChannelInfo();
+
 // Maps the name of the channel to version_info::Channel, always returning
 // Channel::UNKNOWN for unbranded builds. For branded builds defaults to
 // Channel::STABLE, if channel is empty, else matches the name and returns

chrome/common/channel_info_mac.mm

@@ -7,53 +7,101 @@
 #import <Foundation/Foundation.h>
 
 #include "base/mac/bundle_locations.h"
+#include "base/macros.h"
+#include "base/no_destructor.h"
 #include "base/strings/sys_string_conversions.h"
 #include "build/branding_buildflags.h"
 #include "components/version_info/version_info.h"
 
 namespace chrome {
 
-std::string GetChannelName() {
+namespace {
+
+std::string ChannelName() {
 #if BUILDFLAG(GOOGLE_CHROME_BRANDING)
-  // Use the main Chrome application bundle and not the framework bundle.
-  // Keystone keys don't live in the framework.
-  NSBundle* bundle = base::mac::OuterBundle();
-  NSString* channel = [bundle objectForInfoDictionaryKey:@"KSChannelID"];
-
-  // Only ever return "", "unknown", "beta", "dev", or "canary" in a branded
-  // build.
-  // KSProductID is not set (for stable) or "beta", "dev" or "canary" for
-  // the intel-only build.
-  // KSProductID is "arm64" (for stable) or "arm64-beta", "arm64-dev" or
-  // "arm64-canary" for the arm-only build.
-  // KSProductID is "universal" (for stable) or "universal-beta",
-  // "universal-dev" or "universal-canary" for the arm+intel universal binary.
-  if (![bundle objectForInfoDictionaryKey:@"KSProductID"]) {
-    // This build is not Keystone-enabled, it can't have a channel.
-    channel = @"unknown";
-  } else if (!channel || [channel isEqual:@"arm64"] ||
-             [channel isEqual:@"universal"]) {
-    // For the intel stable channel, KSChannelID is not set.
-    channel = @"";
-  } else {
-    if ([channel hasPrefix:@"arm64-"])
-      channel = [channel substringFromIndex:[@"arm64-" length]];
-    else if ([channel hasPrefix:@"universal-"])
-      channel = [channel substringFromIndex:[@"universal-" length]];
-    if ([channel isEqual:@"beta"] || [channel isEqual:@"dev"] ||
-        [channel isEqual:@"canary"]) {
-      // do nothing.
-    } else {
+  static const base::NoDestructor<std::string> channel([] {
+    // Use the main Chrome application bundle and not the framework bundle.
+    // Keystone keys don't live in the framework.
+    NSBundle* bundle = base::mac::OuterBundle();
+    NSString* channel = [bundle objectForInfoDictionaryKey:@"KSChannelID"];
+
+    // Only ever return "", "unknown", "beta", "dev", or "canary" in a branded
+    // build.
+    // KSProductID is not set (for stable) or "beta", "dev" or "canary" for
+    // the intel-only build.
+    // KSProductID is "arm64" (for stable) or "arm64-beta", "arm64-dev" or
+    // "arm64-canary" for the arm-only build.
+    // KSProductID is "universal" (for stable) or "universal-beta",
+    // "universal-dev" or "universal-canary" for the arm+intel universal binary.
+    if (![bundle objectForInfoDictionaryKey:@"KSProductID"]) {
+      // This build is not Keystone-enabled, it can't have a channel.
       channel = @"unknown";
+    } else if (!channel || [channel isEqual:@"arm64"] ||
+               [channel isEqual:@"universal"]) {
+      // For the intel stable channel, KSChannelID is not set.
+      channel = @"";
+    } else {
+      if ([channel hasPrefix:@"arm64-"])
+        channel = [channel substringFromIndex:[@"arm64-" length]];
+      else if ([channel hasPrefix:@"universal-"])
+        channel = [channel substringFromIndex:[@"universal-" length]];
+      if ([channel isEqual:@"beta"] || [channel isEqual:@"dev"] ||
+          [channel isEqual:@"canary"]) {
+        // Do nothing.
+      } else {
+        channel = @"unknown";
+      }
     }
-  }
 
-  return base::SysNSStringToUTF8(channel);
+    return base::SysNSStringToUTF8(channel);
+  }());
+  return *channel;
 #else
   return std::string();
 #endif
 }
 
+bool SideBySideCapable() {
+#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
+  static const base::NoDestructor<bool> capable([] {
+    // Use the main Chrome application bundle and not the framework bundle.
+    // Keystone keys don't live in the framework.
+    NSBundle* bundle = base::mac::OuterBundle();
+    if (![bundle objectForInfoDictionaryKey:@"KSProductID"]) {
+      // This build is not Keystone-enabled, and without a channel assume it is
+      // side-by-side capable.
+      return true;
+    }
+
+    if (GetChannelName().empty()) {
+      // For the stable channel, GetChannelName() returns the empty string.
+      // Stable Chromes are what side-by-side capable Chromes are running
+      // side-by-side *to* and by definition are side-by-side capable.
+      return true;
+    }
+
+    // If there is a CrProductDirName key, then the user data dir of this
+    // beta/dev/canary Chrome is separate, and it can run side-by-side to the
+    // stable Chrome.
+    return [bundle objectForInfoDictionaryKey:@"CrProductDirName"] != nil;
+  }());
+  return *capable;
+#else
+  return true;
+#endif
+}
+
+}  // namespace
+
+void CacheChannelInfo() {
+  ignore_result(ChannelName());
+  ignore_result(SideBySideCapable());
+}
+
+std::string GetChannelName() {
+  return ChannelName();
+}
+
 version_info::Channel GetChannelByName(const std::string& channel) {
 #if BUILDFLAG(GOOGLE_CHROME_BRANDING)
   if (channel.empty())
@@ -69,34 +117,11 @@ version_info::Channel GetChannelByName(const std::string& channel) {
 }
 
 bool IsSideBySideCapable() {
-#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
-  // Use the main Chrome application bundle and not the framework bundle.
-  // Keystone keys don't live in the framework.
-  NSBundle* bundle = base::mac::OuterBundle();
-  if (![bundle objectForInfoDictionaryKey:@"KSProductID"]) {
-    // This build is not Keystone-enabled, and without a channel assume it is
-    // side-by-side capable.
-    return true;
-  }
-
-  if (GetChannelName().empty()) {
-    // For the stable channel, GetChannelName() returns the empty string.
-    // Stable Chromes are what side-by-side capable Chromes are running
-    // side-by-side *to* and by definition are side-by-side capable.
-    return true;
-  }
-
-  // If there is a CrProductDirName key, then the user data dir of this
-  // beta/dev/canary Chrome is separate, and it can run side-by-side to the
-  // stable Chrome.
-  return [bundle objectForInfoDictionaryKey:@"CrProductDirName"];
-#else
-  return true;
-#endif
+  return SideBySideCapable();
 }
 
 version_info::Channel GetChannel() {
-  return GetChannelByName(GetChannelName());
+  return GetChannelByName(ChannelName());
 }
 
 }  // namespace chrome