cc: Cache highp_threshold in TexCoordPrecisionRequired

cc/output/texture_copier.cc

 // Copyright 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 "cc/output/texture_copier.h"
 
 #include "base/debug/trace_event.h"
 #include "build/build_config.h"
 #include "cc/output/gl_renderer.h"  // For the GLC() macro.
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 #include "third_party/khronos/GLES2/gl2.h"
 
 namespace cc {
 
 AcceleratedTextureCopier::AcceleratedTextureCopier(
     WebKit::WebGraphicsContext3D* context,
     bool using_bind_uniforms,
     int highp_threshold_min)
     : context_(context)
     , using_bind_uniforms_(using_bind_uniforms)
-    , highp_threshold_min_(highp_threshold_min) {
+    , highp_threshold_min_(highp_threshold_min)
+    , highp_threshold_cache_(0) {
   DCHECK(context_);
   GLC(context_, fbo_ = context_->createFramebuffer());
   GLC(context_, position_buffer_ = context_->createBuffer());
 
   static const float kPositions[4][4] = { { -1, -1, 0, 1 }, { 1, -1, 0, 1 },
                                           { 1, 1, 0, 1 }, { -1, 1, 0, 1 } };
 
   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, position_buffer_));
   GLC(context_,
       context_->bufferData(
@@ skipping 40 matching lines @@
   GLC(context_,
       context_->bindTexture(GL_TEXTURE_2D, parameters.source_texture));
   GLC(context_,
       context_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST));
   GLC(context_,
       context_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST));
 
   TexCoordPrecision texCoordPrecision = TexCoordPrecisionRequired(
-      context_, highp_threshold_min_, parameters.size);
+      context_, &highp_threshold_cache_, highp_threshold_min_, parameters.size);
   if (texCoordPrecision == TexCoordPrecisionHigh) {
     if (!blit_program_highp_->initialized())
       blit_program_highp_->Initialize(context_, using_bind_uniforms_);
 
     // TODO(danakj): Use EXT_framebuffer_blit if available.
     GLC(context_, context_->useProgram(blit_program_highp_->program()));
   } else {
     if (!blit_program_->initialized())
       blit_program_->Initialize(context_, using_bind_uniforms_);
 
@@ skipping 30 matching lines @@
   GLC(context_, context_->bindTexture(GL_TEXTURE_2D, 0));
 
   GLC(context_, context_->enable(GL_SCISSOR_TEST));
 }
 
 void AcceleratedTextureCopier::Flush() {
   GLC(context_, context_->flush());
 }
 
 }  // namespace cc