Handle EAGAIN error for the mincore syscall used

base/trace_event/process_memory_dump.h

Index: base/trace_event/process_memory_dump.h
diff --git a/base/trace_event/process_memory_dump.h b/base/trace_event/process_memory_dump.h
index 4f7d141104dd3342a26c3263aa2686bf1f20eb5f..58209bc1dfcf7393c8b47247e3d81219b8d4800c 100644
--- a/base/trace_event/process_memory_dump.h
+++ b/base/trace_event/process_memory_dump.h
@@ -48,11 +48,15 @@ class BASE_EXPORT ProcessMemoryDump {
       SmallMap<hash_map<std::string, MemoryAllocatorDump*>>;
 
 #if defined(COUNT_RESIDENT_BYTES_SUPPORTED)
-  // Returns the total bytes resident for a virtual address range, with given
-  // |start_address| and |mapped_size|. |mapped_size| is specified in bytes. The
-  // value returned is valid only if the given range is currently mmapped by the
-  // process. The |start_address| must be page-aligned.
-  static size_t CountResidentBytes(void* start_address, size_t mapped_size);
+  // Counts the total bytes resident for a virtual address range, with given
+  // |start_address| and |mapped_size| and sets |resident_size|. |mapped_size|
+  // is specified in bytes. The value returned is valid only if the given range
+  // is currently mmapped by the process. The |start_address| must be
+  // page-aligned.
+  // Returns true on success.
+  static bool CountResidentBytes(void* start_address,
+                                 size_t mapped_size,
+                                 size_t* resident_size);
 #endif
 
   ProcessMemoryDump(const scoped_refptr<MemoryDumpSessionState>& session_state);