Make GetWebKitRootDirFilePath smarter about where the WebKit root is relative to the chromium root

base/base_paths_mac.mm

Index: base/base_paths_mac.mm
diff --git a/base/base_paths_mac.mm b/base/base_paths_mac.mm
index aed3ea8e3eb787de288e1c702fd120e752be91d8..f86043698aeb189e9e25dd951d17091153890e4c 100644
--- a/base/base_paths_mac.mm
+++ b/base/base_paths_mac.mm
@@ -17,6 +17,9 @@
 #include "base/string_util.h"
 
 namespace {
+// The name of this file relative to the source root. This is used for checking
+// that the source checkout is in the correct place.
+static const char kThisSourceFile[] = "base/base_paths_mac.mm";
 
 void GetNSExecutablePath(FilePath* path) {
   DCHECK(path);
@@ -78,6 +81,14 @@ bool PathProviderMac(int key, FilePath* result) {
         // src/xcodebuild/{Debug|Release}/base_unittests
         *result = result->DirName().DirName();
       }
+      // In a case of a WebKit-only checkout, using make instead of
+      // xcodebuild, we should return <root of
+      // checkout>/Source/WebKit/chromium.
+      // TODO(thakis): try to move the xcodebuild directory up two levels.
+      // http://crbug.com/110455
+      if (!file_util::PathExists(result->Append(kThisSourceFile)))
+        *result = result->Append("Source/WebKit/chromium");

[darin (slow to review), 2012/01/21 00:18:54]

why should src/base know about the directory structure of WebKit?  what happens
when someone wants to refactor the directory structure of WebKit?

+      CHECK(file_util::PathExists(result->Append(kThisSourceFile)));
       return true;
     }
     default: