Removed arbitrary 4096 size limit on WebGL canvas backbuffers

Source/platform/graphics/gpu/DrawingBuffer.cpp

Index: Source/platform/graphics/gpu/DrawingBuffer.cpp
diff --git a/Source/platform/graphics/gpu/DrawingBuffer.cpp b/Source/platform/graphics/gpu/DrawingBuffer.cpp
index aa528a3b761c82c8ed8dd9b4e8eaa86145009398..921199de031989157712021ea049004b5a7385ea 100644
--- a/Source/platform/graphics/gpu/DrawingBuffer.cpp
+++ b/Source/platform/graphics/gpu/DrawingBuffer.cpp
@@ -620,7 +620,8 @@ bool DrawingBuffer::resizeFramebuffer(const IntSize& size)
 
     m_context->bindTexture(GL_TEXTURE_2D, m_colorBuffer.textureId);
 
-    allocateTextureMemory(&m_colorBuffer, size);
+    if (!allocateTextureMemory(&m_colorBuffer, size))
+        return false;
 
     if (m_multisampleMode == ImplicitResolve)
         m_context->framebufferTexture2DMultisampleEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_colorBuffer.textureId, 0, m_sampleCount);
@@ -629,8 +630,10 @@ bool DrawingBuffer::resizeFramebuffer(const IntSize& size)
 
     m_context->bindTexture(GL_TEXTURE_2D, 0);
 
-    if (m_multisampleMode != ExplicitResolve)
-        resizeDepthStencil(size);
+    if (m_multisampleMode != ExplicitResolve) {
+        if (!resizeDepthStencil(size))
+            return false;
+    }
     if (m_context->checkFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
         return false;
 
@@ -649,7 +652,8 @@ bool DrawingBuffer::resizeMultisampleFramebuffer(const IntSize& size)
             return false;
 
         m_context->framebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, m_multisampleColorBuffer);
-        resizeDepthStencil(size);
+        if (!resizeDepthStencil(size))
+            return false;
         if (m_context->checkFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
             return false;
     }
@@ -657,10 +661,10 @@ bool DrawingBuffer::resizeMultisampleFramebuffer(const IntSize& size)
     return true;
 }
 
-void DrawingBuffer::resizeDepthStencil(const IntSize& size)
+bool DrawingBuffer::resizeDepthStencil(const IntSize& size)
 {
     if (!m_requestedAttributes.depth && !m_requestedAttributes.stencil)
-        return;
+        return true;
 
     if (m_packedDepthStencilExtensionSupported) {
         if (!m_depthStencilBuffer)
@@ -701,6 +705,11 @@ void DrawingBuffer::resizeDepthStencil(const IntSize& size)
         }
     }
     m_context->bindRenderbuffer(GL_RENDERBUFFER, 0);
+
+    if (m_context->getError() == GL_OUT_OF_MEMORY)
+        return false;
+
+    return true;
 }
 
 
@@ -963,19 +972,28 @@ void DrawingBuffer::texImage2DResourceSafe(GLenum target, GLint level, GLenum in
     m_context->texImage2D(target, level, internalformat, width, height, border, format, type, 0);
 }
 
-void DrawingBuffer::allocateTextureMemory(TextureInfo* info, const IntSize& size)
+bool DrawingBuffer::allocateTextureMemory(TextureInfo* info, const IntSize& size)
 {
     if (RuntimeEnabledFeatures::webGLImageChromiumEnabled()) {
         deleteChromiumImageForTexture(info);
 
         info->imageId = m_context->createGpuMemoryBufferImageCHROMIUM(size.width(), size.height(), GL_RGBA, GC3D_SCANOUT_CHROMIUM);
+
+        if (m_context->getError() == GL_OUT_OF_MEMORY)
+            return false;
+
         if (info->imageId) {
             m_context->bindTexImage2DCHROMIUM(GL_TEXTURE_2D, info->imageId);
-            return;
+            return true;
         }
     }
 
     texImage2DResourceSafe(GL_TEXTURE_2D, 0, m_internalColorFormat, size.width(), size.height(), 0, m_colorFormat, GL_UNSIGNED_BYTE);
+
+    if (m_context->getError() == GL_OUT_OF_MEMORY)
+        return false;
+
+    return true;
 }
 
 void DrawingBuffer::deleteChromiumImageForTexture(TextureInfo* info)