cc: Make images that can't possibly fit in cache not checker.

cc/tiles/image_decode_cache.h

Index: cc/tiles/image_decode_cache.h
diff --git a/cc/tiles/image_decode_cache.h b/cc/tiles/image_decode_cache.h
index ca1f41e4cd9e5a0ea832d5646d191a99d7b93376..c12fe1a1fbfa18dd6fb7b719bde1b941c23be918 100644
--- a/cc/tiles/image_decode_cache.h
+++ b/cc/tiles/image_decode_cache.h
@@ -96,6 +96,12 @@ class CC_EXPORT ImageDecodeCache {
 
   // Clears all elements from the cache.
   virtual void ClearCache() = 0;
+
+  // Returns the maximum amount of memory we would be able to lock. This ignores
+  // any temporary states, such as throttled, and return the maximum possible
+  // memory. It is used as an esimate of whether an image can fit into the
+  // locked budget before creating a task.
+  virtual size_t GetMaximumMemoryLimit() const = 0;
 };
 
 }  // namespace cc