Change crash keys to be registered with a maximum length instead of number of chunks.

chrome/common/crash_keys.cc

Index: chrome/common/crash_keys.cc
diff --git a/chrome/common/crash_keys.cc b/chrome/common/crash_keys.cc
index f5de54b9b468db7c0376771f3d4d4f73033b56c0..7472d4dbd82eea15f9138f53bf886606e0e3b84b 100644
--- a/chrome/common/crash_keys.cc
+++ b/chrome/common/crash_keys.cc
@@ -4,30 +4,62 @@
 
 #include "chrome/common/crash_keys.h"
 
+#if defined(OS_MACOSX)
+#include "breakpad/src/common/mac/SimpleStringDictionary.h"
+#elif defined(OS_WIN)
+#include "breakpad/src/client/windows/common/ipc_protocol.h"
+#endif
+
 namespace crash_keys {
 
-// TODO(rsesek): This is true on Mac and Linux but not Windows.
-static const size_t kSingleChunkLength = 255;
+// A small crash key, guaranteed to never be split into multiple pieces.
+const size_t kSmallSize = 64;
+
+// A medium crash key, which will be chunked on certain platforms but not
+// others. Guaranteed to never be more than four chunks.
+const size_t kMediumSize = kSmallSize * 4;
+
+// A large crash key, which will be chunked on all platforms. This should be
+// used sparangly.

[Scott Hess - ex-Googler, 2013/02/19 23:16:10]

Sparingly.

[Robert Sesek, 2013/02/27 18:52:49]

Done.

+const size_t kLargeSize = kSmallSize * 16;
+
+#if defined(OS_MACOSX)
+static const size_t kSingleChunkLength =
+    google_breakpad::KeyValueEntry::MAX_STRING_STORAGE_SIZE;
+#elif defined(OS_WIN)
+static const size_t kSingleChunkLength =

[eroman, 2013/02/20 00:04:40]

There is a bit of a mismatch between what the meaning of "length" is:

On Windows breakpad the value can be up to kValueMaxLength-1 characters. As the
final character is required to be NULL.

I think it would be clearer if all the lengths here were defined in terms of
actual data, and not including NULLs. For instance, with three "chunks" you
could fit 63*3 worth of data, compared to this constant suggesting you can fit
64*3.

[Robert Sesek, 2013/02/27 18:52:49]

Done. Same issue on Mac as well.

+    google_breakpad::CustomInfoEntry::kValueMaxLength;
+#else
+static const size_t kSingleChunkLength = 64;
+#endif
+
+// Guarantees for crash key sizes.
+COMPILE_ASSERT(kSmallSize <= kSingleChunkLength,
+               crash_key_chunk_size_too_small);
+#if defined(OS_MACOSX)
+COMPILE_ASSERT(kMediumSize <= kSingleChunkLength,
+               mac_has_medium_size_crash_key_chunks);
+#endif
 
 size_t RegisterChromeCrashKeys() {
   base::debug::CrashKey keys[] = {
     // TODO(rsesek): Remove when done testing. Needed so arraysize > 0.
-    { "rsesek_key", 1 },
+    { "rsesek_key", kSmallSize },
 #if defined(OS_MACOSX)
-    { mac::kFirstNSException, 1 },
-    { mac::kFirstNSExceptionTrace, 1 },
-    { mac::kLastNSException, 1 },
-    { mac::kLastNSExceptionTrace, 1 },
-    { mac::kNSException, 1 },
-    { mac::kSendAction, 1 },
-    { mac::kZombie, 1 },
-    { mac::kZombieTrace, 1 },
+    { mac::kFirstNSException, kMediumSize },
+    { mac::kFirstNSExceptionTrace, kMediumSize },
+    { mac::kLastNSException, kMediumSize },
+    { mac::kLastNSExceptionTrace, kMediumSize },
+    { mac::kNSException, kMediumSize },
+    { mac::kSendAction, kMediumSize },
+    { mac::kZombie, kMediumSize },
+    { mac::kZombieTrace, kMediumSize },
     // content/:
-    { "channel_error_bt", 1 },
-    { "remove_route_bt", 1 },
-    { "rwhvm_window", 1 },
+    { "channel_error_bt", kMediumSize },
+    { "remove_route_bt", kMediumSize },
+    { "rwhvm_window", kMediumSize },
     // media/:
-    { "VideoCaptureDeviceQTKit", 1 },
+    { "VideoCaptureDeviceQTKit", kSmallSize },
 #endif
   };