Move kDcheckIsFatal* flag definitions to be provided cross-platform.

Although these will only be used in official builds on Windows,
providing the flag definitions cross-platform allows developers to
build for other platforms with |dcheck_is_configurable=true| if they
want.

Bug: 812058
Change-Id: I9a53681487e432129001620548e0a62052abab50
Reviewed-on: https://chromium-review.googlesource.com/1012267Reviewed-by: Sigurður Ásgeirsson <siggi@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551191}

chrome/browser/flag_descriptions.cc

@@ -175,6 +175,13 @@ const char kDatasaverPromptDescription[] =
     "Store.";
 const char kDatasaverPromptDemoMode[] = "Demo mode";
 
+#if DCHECK_IS_CONFIGURABLE
+const char kDcheckIsFatalName[] = "DCHECKs are fatal";
+const char kDcheckIsFatalDescription[] =
+    "By default Chrome will evaluate in this build, but only log failures, "
+    "rather than crashing. If enabled, DCHECKs will crash the calling process.";
+#endif  // DCHECK_IS_CONFIGURABLE
+
 const char kDebugPackedAppName[] = "Debugging for packed apps";
 const char kDebugPackedAppDescription[] =
     "Enables debugging context menu options such as Inspect Element for packed "
@@ -2492,13 +2499,6 @@ const char kWindows10CustomTitlebarDescription[] =
     "If enabled, Chrome will draw the titlebar and caption buttons instead of "
     "deferring to Windows.";
 
-#if DCHECK_IS_CONFIGURABLE
-const char kDcheckIsFatalName[] = "DCHECKs are fatal";
-const char kDcheckIsFatalDescription[] =
-    "By default Chrome will evaluate DCHECKs in some Canary builds, but only "
-    "log failed DCHECKs. If enabled, DCHECKs will crash the calling process.";
-#endif  // DCHECK_IS_CONFIGURABLE
-
 #endif  // defined(OS_WIN)
 
 // Mac -------------------------------------------------------------------------

chrome/browser/flag_descriptions.h

@@ -138,6 +138,11 @@ extern const char kDatasaverPromptName[];
 extern const char kDatasaverPromptDescription[];
 extern const char kDatasaverPromptDemoMode[];
 
+#if DCHECK_IS_CONFIGURABLE
+extern const char kDcheckIsFatalName[];
+extern const char kDcheckIsFatalDescription[];
+#endif  // DCHECK_IS_CONFIGURABLE
+
 extern const char kDebugPackedAppName[];
 extern const char kDebugPackedAppDescription[];
 
@@ -1517,11 +1522,6 @@ extern const char kUseWinrtMidiApiDescription[];
 extern const char kWindows10CustomTitlebarName[];
 extern const char kWindows10CustomTitlebarDescription[];
 
-#if DCHECK_IS_CONFIGURABLE
-extern const char kDcheckIsFatalName[];
-extern const char kDcheckIsFatalDescription[];
-#endif  // DCHECK_IS_CONFIGURABLE
-
 #endif  // defined(OS_WIN)
 
 // Mac ------------------------------------------------------------------------