Add discardable memory emulation for non-android/mac platforms

base/memory/discardable_memory.cc

Index: base/memory/discardable_memory.cc
diff --git a/base/memory/discardable_memory.cc b/base/memory/discardable_memory.cc
index 33f9e19cdeee523f7b99a53a8452ef23f0f569f0..06a36ecbcdffbb9b593e499da6ec0dbd358d89be 100644
--- a/base/memory/discardable_memory.cc
+++ b/base/memory/discardable_memory.cc
@@ -16,51 +16,13 @@ DiscardableMemory::DiscardableMemory()
       , fd_(-1)
 #endif  // OS_ANDROID
       {
-  DCHECK(Supported());
 }
 
 void* DiscardableMemory::Memory() const {
-  DCHECK(is_locked_);
+  if (!is_locked_)
+    // This is a fatal error, and we must die.
+    CHECK(false);

[Avi (use Gerrit), 2013/06/18 00:00:46]

Braces if the if spans more than one line. (Even if that second line is a
comment.)

   return memory_;
 }
 
-// Stub implementations for platforms that don't support discardable memory.
-
-#if !defined(OS_ANDROID) && !defined(OS_MACOSX)
-
-DiscardableMemory::~DiscardableMemory() {
-  NOTIMPLEMENTED();
-}
-
-// static
-bool DiscardableMemory::Supported() {
-  return false;
-}
-
-bool DiscardableMemory::InitializeAndLock(size_t size) {
-  NOTIMPLEMENTED();
-  return false;
-}
-
-LockDiscardableMemoryStatus DiscardableMemory::Lock() {
-  NOTIMPLEMENTED();
-  return DISCARDABLE_MEMORY_FAILED;
-}
-
-void DiscardableMemory::Unlock() {
-  NOTIMPLEMENTED();
-}
-
-// static
-bool DiscardableMemory::PurgeForTestingSupported() {
-  return false;
-}
-
-// static
-void DiscardableMemory::PurgeForTesting() {
-  NOTIMPLEMENTED();
-}
-
-#endif  // OS_*
-
 }  // namespace base