Adding support for sampling crashes in Chrome on Windows.

chrome/install_static/install_util.cc

Index: chrome/install_static/install_util.cc
diff --git a/chrome/install_static/install_util.cc b/chrome/install_static/install_util.cc
index c31b90e8927cd71f4cedf026d3b44da0f2112046..a9965159a5d60b4cf168d3710ddfe697bf85e7ab 100644
--- a/chrome/install_static/install_util.cc
+++ b/chrome/install_static/install_util.cc
@@ -55,6 +55,8 @@ const wchar_t kAppGuidGoogleChrome[] =
 const wchar_t kAppGuidGoogleBinaries[] =
     L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
 
+const wchar_t kChromeStatsSampleKey[] = L"UsageStatsInSample";

[Alexei Svitkine (slow), 2016/08/12 17:47:48]

How about using a similar variable naming convention as kRegValueUsageStats?

e.g. kRegValueUsageStatsInSample

(Although, I guess this convention isn't constently followed - still I prefer
you at least make it match some existing style rather than adding a whole new
one.)

[jwd, 2016/08/12 20:04:30]

Done.

+
 const wchar_t kHeadless[] = L"CHROME_HEADLESS";
 const wchar_t kShowRestart[] = L"CHROME_CRASHED";
 const wchar_t kRestartInfo[] = L"CHROME_RESTART";
@@ -234,6 +236,12 @@ bool RecursiveDirectoryCreate(const std::wstring& full_path) {
   return true;
 }
 
+std::wstring GetChromeInstallRegistryPath() {
+  std::wstring registry_path = L"Software\\";
+  registry_path += GetChromeInstallSubDirectory();
+  return registry_path;
+}
+
 bool GetCollectStatsConsentImpl(const std::wstring& exe_path) {
   bool enabled = true;
   bool controlled_by_policy = ReportingIsEnforcedByPolicy(&enabled);
@@ -412,6 +420,33 @@ bool GetCollectStatsConsentForTesting(const std::wstring& exe_path) {
   return GetCollectStatsConsentImpl(exe_path);
 }
 
+bool GetCollectStatsInSample() {
+  std::wstring registry_path = GetChromeInstallRegistryPath();
+
+  DWORD out_value = 0;
+  if (!nt::QueryRegValueDWORD(nt::HKCU, registry_path.c_str(),
+                              kChromeStatsSampleKey, &out_value)) {
+    // If reading the value failed, treat it as though sampling isn't in effect,
+    // implicitly meaning this install in in-sample.

[Alexei Svitkine (slow), 2016/08/12 17:47:48]

Nit: "this install in sample" -> "this install is in the sample"

[jwd, 2016/08/12 20:04:30]

Done.

+    return true;
+  }
+  return out_value == 1;
+}
+
+bool SetCollectStatsInSample(bool in_sample) {
+  std::wstring registry_path = GetChromeInstallRegistryPath();
+
+  HANDLE key_handle = INVALID_HANDLE_VALUE;
+  if (!nt::CreateRegKey(nt::HKCU, registry_path.c_str(), KEY_SET_VALUE,
+                        &key_handle)) {
+    nt::CloseRegKey(key_handle);
+    return false;
+  }
+
+  return nt::SetRegValueDWORD(key_handle, kChromeStatsSampleKey,
+                              in_sample ? 1 : 0);
+}
+
 bool ReportingIsEnforcedByPolicy(bool* metrics_is_enforced_by_policy) {
   DWORD value = 0;
 
@@ -678,8 +713,7 @@ std::wstring GetChromeInstallSubDirectory() {
 }
 
 std::wstring GetBrowserCrashDumpAttemptsRegistryPath() {
-  std::wstring registry_path = L"Software\\";
-  registry_path += GetChromeInstallSubDirectory();
+  std::wstring registry_path = GetChromeInstallRegistryPath();
   registry_path += kBrowserCrashDumpMetricsSubKey;
   return registry_path;
 }