cc: Use highp precision for texture coords if available and needed

cc/debug/fake_web_graphics_context_3d.cc

 // Copyright 2013 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/debug/fake_web_graphics_context_3d.h"
 
+#include "base/logging.h"
 #include "third_party/khronos/GLES2/gl2.h"
 
 using WebKit::WGC3Dboolean;
 using WebKit::WGC3Denum;
 using WebKit::WebGLId;
 using WebKit::WebGraphicsContext3D;
 
 namespace cc {
 
 FakeWebGraphicsContext3D::FakeWebGraphicsContext3D()
@@ skipping 128 matching lines @@
     WebKit::WGC3Dint* value) {
   if (pname == GL_COMPILE_STATUS)
     *value = 1;
 }
 
 WebKit::WebString FakeWebGraphicsContext3D::getShaderInfoLog(
     WebGLId shader) {
   return WebKit::WebString();
 }
 
+void FakeWebGraphicsContext3D::getShaderPrecisionFormat(
+    WebKit::WGC3Denum shadertype,
+    WebKit::WGC3Denum precisiontype,
+    WebKit::WGC3Dint* range,
+    WebKit::WGC3Dint* precision) {
+  // Return the minimum precision requirements of the GLES specificatin.
+  switch (precisiontype) {
+    case GL_LOW_INT:
+      range[0] = 8;
+      range[1] = 8;
+      *precision = 0;
+      break;
+    case GL_MEDIUM_INT:
+      range[0] = 10;
+      range[1] = 10;
+      *precision = 0;
+      break;
+    case GL_HIGH_INT:
+      range[0] = 16;
+      range[1] = 16;
+      *precision = 0;
+      break;
+    case GL_LOW_FLOAT:
+      range[0] = 8;
+      range[1] = 8;
+      *precision = 8;
+      break;
+    case GL_MEDIUM_FLOAT:
+      range[0] = 14;
+      range[1] = 14;
+      *precision = 10;
+      break;
+    case GL_HIGH_FLOAT:
+      range[0] = 62;
+      range[1] = 62;
+      *precision = 16;
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
 WebKit::WebString FakeWebGraphicsContext3D::getShaderSource(
     WebGLId shader) {
   return WebKit::WebString();
 }
 
 WebKit::WebString FakeWebGraphicsContext3D::getString(WGC3Denum name) {
   return WebKit::WebString();
 }
 
 WebKit::WGC3Dint FakeWebGraphicsContext3D::getUniformLocation(
@@ skipping 125 matching lines @@
 
 void FakeWebGraphicsContext3D::setContextLostCallback(
     WebGraphicsContextLostCallback* callback) {
 }
 
 void FakeWebGraphicsContext3D::loseContextCHROMIUM(WGC3Denum current,
                                                    WGC3Denum other) {
 }
 
 }  // namespace cc