Disable 5ms flusher on Android to reduce kernel thrashing.

gpu/command_buffer/client/cmd_buffer_helper.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains the implementation of the command buffer helper class.
 
 #include "../client/cmd_buffer_helper.h"
 #include "../common/command_buffer.h"
 #include "../common/trace_event.h"
 
@@ skipping 161 matching lines @@
   }
   // Force a flush if the buffer is getting half full, or even earlier if the
   // reader is known to be idle.
   int32 pending =
       (put_ + usable_entry_count_ - last_put_sent_) % usable_entry_count_;
   int32 limit = usable_entry_count_ /
       ((get_offset() == last_put_sent_) ? 16 : 2);
   if (pending > limit) {
     Flush();
   } else if (commands_issued_ % kCommandsPerFlushCheck == 0) {
+#if !defined(OS_ANDROID)
     // Allow this command buffer to be pre-empted by another if a "reasonable"
-    // amount of work has been done.
+    // amount of work has been done. On highend machines, this reduces the
+    // latency of GPU commands. However, on Android, this can cause the
+    // kernel to thrash between generating GPU commands and executing them.
     clock_t current_time = clock();
     if (current_time - last_flush_time_ > kFlushDelay * CLOCKS_PER_SEC)
       Flush();
+#endif
   }
 }
 
 CommandBufferEntry* CommandBufferHelper::GetSpace(uint32 entries) {
   ++commands_issued_;
   WaitForAvailableEntries(entries);
   CommandBufferEntry* space = &entries_[put_];
   put_ += entries;
   GPU_DCHECK_LE(put_, usable_entry_count_);
   if (put_ == usable_entry_count_) {
     cmd::Jump::Set(&entries_[put_], 0);
     put_ = 0;
   }
   return space;
 }
 
 error::Error CommandBufferHelper::GetError() {
   CommandBuffer::State state = command_buffer_->GetState();
   return static_cast<error::Error>(state.error);
 }
 
 }  // namespace gpu