WebGL: Remove some unused members in WebGLRenderingContext.

Source/core/html/canvas/WebGLRenderingContext.h

Index: Source/core/html/canvas/WebGLRenderingContext.h
diff --git a/Source/core/html/canvas/WebGLRenderingContext.h b/Source/core/html/canvas/WebGLRenderingContext.h
index 04c7c95a09b6266ed5859dbbada6ecf0cdd2651f..b49c64844d99b6a49e0893acb3cb8a20283a4ac3 100644
--- a/Source/core/html/canvas/WebGLRenderingContext.h
+++ b/Source/core/html/canvas/WebGLRenderingContext.h
@@ -522,7 +522,6 @@ public:
     GLuint m_onePlusMaxEnabledAttribIndex;
     unsigned long m_onePlusMaxNonDefaultTextureUnit;
 
-    bool m_preserveDrawingBuffer;
     OwnPtr<Extensions3DUtil> m_extensionsUtil;
 
     // Enabled extension objects.
@@ -612,7 +611,7 @@ public:
         {
         }
 
-        ~TypedExtensionTracker()
+        virtual ~TypedExtensionTracker()

[Ken Russell (switch to Gerrit), 2014/02/19 20:23:10]

This change is unnecessary because ExtensionTracker's destructor is virtual.

#include <iostream>

using namespace std;

class A {
 public:
  A() { cout << "A::A()" << endl; }
  virtual ~A() { cout << "A::~A()" << endl; }
};

class B : public A {
 public:
  B() { cout << "B::B()" << endl; }
  ~B() { cout << "B::~B()" << endl; }
};

int main(int argc, char** argv) {
  A* p = new B();
  delete p;
}

[piman, 2014/02/19 20:28:24]

There's a style rule in chromium land that says that overriding methods (and
destructor) should be marked virtual for clarity.
Is it not the case in blink land?

[Ken Russell (switch to Gerrit), 2014/02/19 21:08:13]

I'd forgotten so went back and looked. The Blink style guide is silent on this
issue so the Google C++ style guide should be used. Yes, you're right, the
derived class should use the "virtual" keyword.

However, there is no memory leak in the current code, so the CL description is
wrong. It should say something like "Mark TypedExtensionTracker's destructor
virtual for clarity."

         {
             if (m_extensionField) {
                 m_extensionField->lose(true);
@@ -698,12 +697,6 @@ public:
     // Helper function to get the bound framebuffer's color buffer format.
     GLenum boundFramebufferColorFormat();
 
-    // Helper function to get the bound framebuffer's width.
-    int boundFramebufferWidth();
-
-    // Helper function to get the bound framebuffer's height.
-    int boundFramebufferHeight();
-
     // Helper function to verify limits on the length of uniform and attribute locations.
     bool validateLocationLength(const char* functionName, const String&);