Use gpu::SharedMemoryLimits for in process GL contexts.

android_webview/browser/aw_render_thread_context_provider.cc

Index: android_webview/browser/aw_render_thread_context_provider.cc
diff --git a/android_webview/browser/aw_render_thread_context_provider.cc b/android_webview/browser/aw_render_thread_context_provider.cc
index 93251fa6604a923d66b63f99a0db2a4858fd6abc..750e9ba3a5e8cdc7e5237bff40259a19637380e5 100644
--- a/android_webview/browser/aw_render_thread_context_provider.cc
+++ b/android_webview/browser/aw_render_thread_context_provider.cc
@@ -13,6 +13,7 @@
 #include "gpu/command_buffer/client/gl_in_process_context.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "gpu/command_buffer/client/gles2_lib.h"
+#include "gpu/command_buffer/client/shared_memory_limits.h"
 #include "gpu/skia_bindings/gl_bindings_skia_cmd_buffer.h"
 #include "third_party/skia/include/gpu/GrContext.h"
 #include "third_party/skia/include/gpu/gl/GrGLInterface.h"
@@ -50,11 +51,15 @@ AwRenderThreadContextProvider::AwRenderThreadContextProvider(
   attributes.samples = 0;
   attributes.sample_buffers = 0;
   attributes.bind_generates_resource = false;
+
+  gpu::SharedMemoryLimits limits;
+  // TODO(boliu): Why?
+  limits.start_transfer_buffer_size = 4 * 1024 * 1024;

[danakj, 2016/04/20 02:13:53]

I took this from the old defaults which were different from the ones that were
in WebGraphicsContext3DCommandBufferImpl, for some reason?

[boliu, 2016/04/20 02:39:23]

This only runs the delegated compositor, which is draw quads only, and no
upload, right? Can we save some memory by lowering this to like something tiny?
That'd be great :p

[danakj, 2016/04/20 21:55:02]

Stealing from compositor_impl_android then.

+
   context_.reset(gpu::GLInProcessContext::Create(
       service, surface, surface->IsOffscreen(), gfx::kNullAcceleratedWidget,
       surface->GetSize(), nullptr /* share_context */, attributes,
-      gfx::PreferDiscreteGpu, gpu::GLInProcessContextSharedMemoryLimits(),
-      nullptr, nullptr));
+      gfx::PreferDiscreteGpu, limits, nullptr, nullptr));
 
   context_->GetImplementation()->SetLostContextCallback(base::Bind(
       &AwRenderThreadContextProvider::OnLostContext, base::Unretained(this)));