android: Tweak readback context memory limits

content/browser/renderer_host/render_widget_host_view_android.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/renderer_host/render_widget_host_view_android.h"
 
 #include <android/bitmap.h>
 
 #include <utility>
 
@@ skipping 178 matching lines @@
   attributes.bind_generates_resource = false;
 
   gpu::SharedMemoryLimits limits;
   // The GLHelper context doesn't do a lot of stuff, so we don't expect it to
   // need a lot of space for commands.
   limits.command_buffer_size = 1024;
   // The transfer buffer is used for shaders among other things, so give some
   // reasonable but small limit.
   limits.start_transfer_buffer_size = 4 * 1024;
   limits.min_transfer_buffer_size = 4 * 1024;
-
-  // Use the largest available display size as the max texture size.
-  constexpr size_t kBytesPerPixel = 4;
-  size_t max_screen_texture_size_in_bytes = limits.min_transfer_buffer_size;
-  for (auto& display : display::Screen::GetScreen()->GetAllDisplays()) {
-    gfx::Size size = display.GetSizeInPixel();
-    size_t display_size_in_bytes =
-        kBytesPerPixel * size.width() * size.height();
-    if (display_size_in_bytes > max_screen_texture_size_in_bytes)
-      max_screen_texture_size_in_bytes = display_size_in_bytes;
-  }
-
-  limits.max_transfer_buffer_size = max_screen_texture_size_in_bytes;
-  // This context is used for doing async readbacks, so allow at least a full
-  // screen readback to be mapped.
-  limits.mapped_memory_reclaim_limit = max_screen_texture_size_in_bytes;
+  limits.max_transfer_buffer_size = 128 * 1024;;

[danakj, 2017/01/18 23:21:55]

double ;;

[boliu, 2017/01/19 00:00:50]

oops, fixed

+  // Very few allocations from mapped memory pool, so this can be really low.
+  limits.mapped_memory_reclaim_limit = 4 * 1024;
 
   constexpr bool automatic_flushes = false;
   constexpr bool support_locking = false;
   const GURL url("chrome://gpu/RenderWidgetHostViewAndroid");
 
   provider_ = new ui::ContextProviderCommandBuffer(
       std::move(gpu_channel_host), gpu::GPU_STREAM_DEFAULT,
       gpu::GpuStreamPriority::NORMAL, gpu::kNullSurfaceHandle, url,
       automatic_flushes, support_locking, limits, attributes, nullptr,
       ui::command_buffer_metrics::BROWSER_OFFSCREEN_MAINTHREAD_CONTEXT);
@@ skipping 1847 matching lines @@
   if (!compositor)
     return;
 
   overscroll_controller_ = base::MakeUnique<OverscrollControllerAndroid>(
       overscroll_refresh_handler, compositor,
       ui::GetScaleFactorForNativeView(GetNativeView()));
   is_showing_overscroll_glow_ = true;
 }
 
 }  // namespace content